Eleventh-Hour Superpower

"Make the final effort! Shoot the star to defeat the final enemy!"

- The Star Rod's description, Kirby's Adventure

This is when the final Boss Battle is spent with some sort of Power-Up or item or equipment not found anywhere else in the game. Presumably, it's the only way that boss can be defeated (possibly indicated by a Hopeless Boss Fight beforehand). The probable reason it's only available in this fight is that it would severely screw up game balance if it was available anywhere else. Purposefully Overpowered usually ensues.

Developers should exercise caution when using this trope. Done well, it can make for an exhilarating experience. Done poorly, it can feel like a massive cop-out.

See also the Sword of Plot Advancement, which is more of an Eighth Hour Superpower.

Contrast Second-Hour Superpower, which is a powerup, item, or equipment you receive by the end of the tutorial level usually. Also contrast A Taste of Power, which is basically a First Hour Superpower. A subtrope is the Last-Disc Magic.

Video Game examples

 * The Dark Energy Gravity Gun in Half Life 2 that appears in the penultimate level. Different only in that it's available for the last several levels instead of merely the final boss fight. It's also the only weapon you can use for these sections, requiring a bit of extra work; its range is still limited, but since it was rather good to begin with, and it now causes instant death of a bone-breaking, muscle-dislocating nature in all humanoid enemies (the only kind you'll face until the strider halfway through and the two gunships at the very end) and can rip bolted-down wall monitors with Breen on them ranting at you off the wall with a simple yank, this hardly matters. It is also very, very fun.
 * Episode 1 inverts this. It takes place directly after the events of Half Life 2, and thus you get to use the Dark Energy Gravity Gun for the first few levels of the game. Then you lose it and go back to whacking zombies with bricks.
 * Word of God (the in-game commentary) explains that the developers made the specific decision to give the player all the weapons in reverse. You start with the Dark Energy Gravity Gun, then get the Rocket Launcher, and so on...until the last weapon you get: the crowbar.
 * Since Word of God says we won't ever see the Dark Energy Gravity Gun again, Episode 2 gave us the Magnusson Device, which is an instant kill if mounted on a Strider and detonated.
 * In Resistance 2, Hale defeats the Big Bad and absorbs his psychic powers, which reduce chimeras to chunky salsa. After a brief rampage, however, it turns out it wasn't probably wasn't for the best.
 * The very-definitely-final boss of Parasite Eve is impervious to everything you use on it - bullets, rockets, shotguns, ultimate techniques... and then the main character is given bullets laced with her own DNA, lethal to the creature's own cellular structure. The resumed boss fight takes less than a minute to complete.
 * Well, very nearly impervious. The boss still takes 1HP damage from every attack, so in theory it can be beaten. But, considering that the boss has about 3000 HP, and that the number of bullets/ordnance you can carry is limited, AND it can one-hit kill you...just use the damn special bullets.
 * Most of the Sonic the Hedgehog games from Sonic And Knuckles on end with a boss fight in Super Mode, though the ability was unlockable in normal gameplay as well up until Sonic Adventure, at which point it became a true Eleventh Hour Superpower.
 * Sonic and the Secret Rings and Sonic and the Black Knight did things slightly differently, giving you Darkspine Sonic and Excalibur-Sonic, respectively.
 * Averted in the Wii version of Sonic Colors, where the Nega-Wisp Armor is fought as normal Sonic and Super Sonic is once again unlockable for normal gameplay.
 * Played straight in the DS version, however. Collecting all the Chaos Emeralds just unlocks the True Final Boss, the Nega-Mother Wisp, which is once again, a standard use Super Sonic in space level. Super Sonic doesn't carry over to the regular levels.
 * Generations has the final boss as both Super Sonics, and after that they are unlocked for use in normal stages, as an equippable skill that can only be used on its own.
 * Summon Night: Swordcraft Story and Summon Night: Swordcraft Story 2 gives you the ultimate weapon before fighting the final boss.
 * Sly Cooper gains the ability to walk on light beams mere moments before the final boss fight in Sly 3.
 * The Silver Arrows (or their cooler counterpart the Light Arrows) in several of the Legend of Zelda games.
 * The original The Legend of Zelda had the Silver Arrows appear only in the last labyrinth, where they were required to defeat Ganon. The Red Ring reduces damage taken to 1/4 of its base, but is only found in the eighth labyrinth - the game's open-ended structure allows sufficiently skilled players to subvert this trope and grab both without fully completing the other labyrinths.
 * In The Legend of Zelda: The Wind Waker, the Light Arrows are a one-shot kill on almost everything.
 * Also, specifically in The Legend of Zelda: Majora's Mask, the ludicrously powerful Fierce Deity's Mask, although you had to meet certain conditions first. The Giant Mask is a more localized example, as it's only usable in one boss room in the entire game - it becomes an example proper as part of the conditions for obtaining the Fierce Deity's Mask.
 * In The Legend of Zelda: Phantom Hourglass, Link's fairy companion randomly and without warning pulls the ability to stop time from nowhere in the first part of the Final Boss Fight. This continues on to the second and third rounds, as well.
 * The final Great Fairy in The Legend of Zelda: Ocarina of Time doubles your defense, but can only be reached using the Golden Gauntlets, which are found in the last dungeon.
 * Doing the fusion with Nemesis for the fight against Apocalypse in Silver.
 * Dante's Sparda Devil Trigger in the first Devil May Cry.
 * And to a lesser extent, the "Dark Slayer" Style in Devil May Cry 4, gained at the start of Dante's last mission. However, it is balanced against Dante's other styles, and isn't nearly as overpowered as most other examples.
 * Also, the New Game+ element of the game results in you being able to permanently use it in all following playthroughs. Dark Slayer Style is actually an example of an ability that was obviously designed to be used with New Game Plus, as it is not particularly useful against Dante's final boss.
 * In Soul Calibur, Xianghua's mother's keepsake revealed itself to be the titular sword, which Xianghua would use to defeat Inferno. Gameplay and Story Segregation turns it into a subversion, as it isn't any better in battle than the Krita-Yuga was.
 * In the final battle of Gungrave: Overdose, your character is filled with so much rage that his appearance changes slightly (Beyond the Grave's eye glows completely white and his hair goes super-saiyan-ish, Rocketbilly suddenly becomes shirtless, and Jyuji wears Bunji's shades and the flame on his back turns blue). The demolition shot gauge then begins to regenerate and fill up on its own, which lets you use your D. Shots more frequently.
 * Happens to an extent in Knights of the Old Republic II, when after  get either the dark side uberpower Force Crush or the Light Side uberpower Force Enlightenment, both of which are probably the best power for their respective alignments.
 * Throughout Little Nemo the Dream Master, your only weapons are thrown candy, which does no more than stun enemies, and whatever abilities are granted by the animals you charm. In the last level Nightmare Land, however, you are given the Royal Scepter which fires actual damaging projectiles.
 * The powers granted by the five orbs in Onimusha 2, resulting in an Unexpected Gameplay Change into a
 * In Dawn of Dreams, for one part of the final boss fight, Soki is given the Oni Gauntlet (which holds the soul and power of Nobunaga Oda), allowing him to transform into a huge, heavily-armored ogre warrior. He can fly and use both of his swords at once, as well as getting a new skill called "Ultimate Counter".
 * For the final level in Prince of Persia: The Sands of Time, your awesome time-controlling dagger gets taken away, but you're given a sword that one-hit-kills any of the sand monsters, so fights generally go really fast. Then the sword gets taken away and the dagger is given back for the final boss fight (although the boss was human, so the sword probably wouldn't've worked on him anyway).
 * Happens a lot in Resident Evil games:
 * In the original Resident Evil 1, Resident Evil 2, and Resident Evil 4, you are thrown a rocket launcher with which you take out the final boss in the game. Meanwhile, Resident Evil 3: Nemesis ends with the player coincidentally finding the big boss in the same room as a giant stationary rail gun.
 * In 4 you can actually beat Saddler without the rocket launcher, though this is very difficult and a lot less fun. There are also less powerful rocket launchers available throughout the game, which will kill every other boss with one shot.
 * While it wasn't used on the final boss, the killsat from Resident Evil 5 deserves a mention (imagine facing zombies with THAT).
 * During the Final Battle with Evelyn in Resident Evil 7: Biohazard, Ethan's weapons are completely ineffective against the house-sized monstrosity she has transformed into, her regeneration powers making her unstoppable. It seems hopeless, until a squad of Blue Umbrella soldiers (led by Chris Redfield himself) finally arrive and throw him a box of special ammunition called R.A.M.R.O.Ds (Rapid-Acting Mycetotoxic ROunDs) which are specially designed to neutralize the regenerative abilities of the Umbrella Corporation's evil biochemical creations. Combining this weapon with the necrotoxin he initially was using, Ethan finally manages to defeat Evelyn.
 * In Planescape: Torment, the powerful "Symbol of Torment" is not available until the very final scenes of the game. Given the many ways available to deal with the final boss without fighting him, chances are good it never sees any use.
 * In addition, one of the Nameless One's normal abilities acquired at the beginning of the game is the ability to raise people from the dead, albeit with a lot of limitations. It doesn't come out until the very end that
 * While some Fire Emblem games partially avert this by making some legendary weapons available early on, they still qualify by not making The Hero's available until the final few chapters. In addition, most games in the series feature a super-powerful recruit who only joins for the final chapter. This character archetype is so common that it's got a nickname among the Fire Emblem community: the "Gato", after its first example. Others include Karel from Fire Emblem 6, Athos from Fire Emblem 7, and two Laguz kings and a third's top General from Fire Emblem 9.
 * Ragnell in Fire Emblem 9: Path of Radiance. It's only usable for two-and-a-half chapters (out of more than thirty) in the entire game, but it's by far the best usable sword, being one of only two Unbreakable Weapons in the entire game, with good attack power and a ranged attack to boot. It allows the main character—who's arguably the best character in the game even with normal weapons—to rip through enemy hordes damn near single-handedly, and is the only equippable weapon that can damage the final boss.
 * Ragnell goes to plot-defying lengths to conform to this trope. Ike presumably gets Ragnell much earlier in the storyline, but it doesn't appear in-game until the 3rd last chapter. Even then, the sword waits until the end of that chapter to magically appear in Ike's inventory at which point it becomes vital to use.
 * But in an ironic twist of fate, Ragnell averts this trope in Super Smash Bros.. Brawl. When Ike uses it there, it's no more or less powerful than any other sword.
 * The sequel, Radiant Dawn, kicks this up another notch. In one of the last five chapters, you obtain  You also get   before those final five chapters. Add to that that after 2 chapters you can make a weapon unbreakable for every character, you get a lot of these this game. On second playthrough on you get
 * Additionally, while it's only the Eleventh Hour Superpower of Part 1 (of four) only, you also get, but he still has a death speech.
 * A notable example is the titular "Sword Of Seals" in Fire Emblem: The Binding Blade since it allowed you to dominate the remaining chapter (chapters if you had all of the other legendary weapons) with almost complete ease.
 * The only real problem with it is that only the main character can use it. Which wouldn't be a problem normally (Roy's a pretty good character), but the problem is that Roy doesn't class change until he gets the sword. What this means is that you're going up against basically level 36 enemies with someone at max level 21. Oh, that and the whole only 20 uses thing.
 * The Narga tome from Fire Emblem 4 also counts, as you get it nearly right before fighting the final boss, and it has 30 Might (though all holy weapons are that powerful) and adds a grand total of 80 points in stat bonuses (Most legendary weapons in 4 provide a total of 30 bonus stat points... while in other entries in the series, legendaries rarely provide over 5 bonus stat points) and negates the final boss's ability to halve attack power. It also summons a giant glowing dragon to attack.
 * Frequently used in the Metroid series. In Super Metroid, the all-powerful Hyper Beam is granted to Samus halfway through the final boss battle for use there and during the Load-Bearing Boss escape sequence. In Metroid Prime, the Phazon Beam serves a similar purpose (your HUD even reads "Hyper Mode"). In fact, since Super Metroid, every game in the series has had an anti-final-boss weapon of this sort—except Prime 2, where the boss has your uber-weapon from last time and you have to turn it back on her. Metroid Prime: Hunters features the Omega Cannon, which can later be unlocked for multiplayer. Metroid Fusion is unique in that the boss-killing superweapon is the Ice Beam, a series staple which is typically gained midway through the game. Metroid Prime 3 also put a twist on it by giving you access to the uber-weapon only a few hours in but limiting its usage; when the endgame hits, you lose access to all weapons but that one.
 * In Metroid: Other M, the Power Bombs function as the ultimate boss-killing weapon. Too bad the game doesn't tell you they have been enabled. You keep them in the Playable Epilogue.
 * Dart's Divine Dragoon transformation and Rose's Dragon Buster sword in Legend of Dragoon. Although you can backtrack through the last dungeon (but not out of it), you receive it literally just before the final boss.
 * Pandora's Box in the first God of War, and the Blade of Olympus in the sequel (although you could also use the Blade for a little while in the beginning of the game).
 * Pandora's Box didn't really do anything, just made you bigger to fight Ares. Once you got to that size, it was no different from normal play, so there was no advantage.
 * The story states it would give the power to kill a god, so while it did seem to just make Kratos bigger, chances are if he just went up to Ares(even a normal sized Ares) and tried to stab him without the power of the box, it wouldn't have worked out so well. More of a storyline boost, but still.
 * The Kirby series has things such as the Star Rod, Starship, Master sword, Triple-Star, Landia and the Star Allies Sparkler, whether they're for Unexpected Shmup Level s, Final Boss fight s, or both.
 * SaGa Frontier does this no fewer than three times: In Blue's game, after mastering magic after the battle with Rouge, finding T260's Omega Model body in the penultimate dungeon, and Red only gets learns Re-Al-Phoenix after he uses Al-Phoenix on .]]
 * At the end of Star Trek Elite Force, you encounter a recharge station that increases your health and ammunition to far beyond the previously imposed limits, just before the climactic battle.
 * Dirge of Cerberus has Vincent Valentine transform into Chaos and pull his ultimate weapon Death Penalty out of thin air for the final level.
 * Not to mention the original game gives you Omnislash if you didn't get Sidetracked by the Gold Saucer and grind for it earlier.
 * Lost Planet: Extreme Condition gives you an incredibly agile, flight-capable Vital Suit very near the end of the game; prior only to a short corridor of enemies (to learn the controls) and the final boss. The suit controls so differently than any other that it might be considered an Unexpected Gameplay Change.
 * Zone of the Enders: the 2nd Runner has two of these. The first is Jehuty Version 2, gained just before the final dungeon, which is twice as strong as normal Jehuty. The second is Naked Jehuty, gained just before the final boss, which is ten times stronger than version 2 and can tear through former bosses like wet tissue paper.
 * In Shin Megami Tensei: Digital Devil Saga 2, Serph in The Very Definitely Final Dungeon (also a Point of No Return).
 * Done incredibly well in the game The Darkness. The final part of the game, an attack on the Big Bad's mansion, takes place during a solar eclipse which massively augments your darkness-based powers. Might not sound all that impressive until you actually see what you're capable of (and by "see" I mean that the majority of this attack is made up of cutscenes that showcase your newfound power). Darklings, goblin-like minions spawned in small numbers to help you out, are spawning of their own accord by the dozen and swarm all over the place. The Black Hole ability, which...well...creates small black holes, is powerful enough to rip walls to pieces and pull in enemies from dozens of metres away. The Darkness Shield, which protects you from attacks, is strong enough to withstand a minigun barrage from a helicopter gunship. The Demon Arm, a spiked tendril used to impale enemies and throw them about, is used by the protagonist to pluck said gunship out of the sky and smash it to pieces. The only ability that doesn't demonstrate any obvious increase in power is Creeping Dark, a wall-crawling demon head used to scout distant areas and attack from safety, but it still puts the fear of God into the mooks you're fighting to the point where one of them throws himself through an upper-story window to escape from it.
 * Either Li, Yuan or Sammo from the Inheritance chapter of Live a Live, depending on who the Xin Shan Quan Master's Inheritor is, is granted one shot of their level 16 attack, Xuan Ya Lian Shan Quan, for the last boss battle of their chapter. This attack usually knocks off 1/3 to 1/2 of the boss' health. Since it's unlikely, verging on impossible for any of these characters to hit level 16 during their chapter, this counts as an Eleventh Hour Superpower. Of course, in the game's FINAL chapter, it's entirely possible, if not exceptionally easy, for these characters to hit level 16 and become gods of death, seeing as this is the only level 16 technique, save for Pogo's (which causes sizable stat debuffs on him after use), that fires off as soon as you select it.
 * Not a traditional game per se, but Avalon in Fate/stay night's "Fate" route work as such. Avalon is only returned to Saber before the final battle, who uses it when she was losing for a comeback victory (Shirou also Traces a copy, and does the same for his battle). Arguably, Unlimited Blade Works (in the route of the same name) and both the aptly-named Rule Breaker and Excalibur (in Heaven's Feel) also perform the same function.
 * In X-Men Legends II: The Rise of Apocalypse, you get to try out the powers of the Four long enough to trash Apocalypse's powering-up device (it's the only way to do it, and if you don't, Apocalypse simply revives there the instant you defeat him.
 * While this isn't really a solely end-game instance, it IS very late in the game and only available to one class. In Quest for Glory IV, as a Wizard, you get Erana's Staff (Erana, for those unfamiliar, was an extremely, EXTREMELY powerful magic user who, with her magic, managed to enchant no fewer than six different places as "Peaceful" areas, where no violence of any form can work. In QFG 3, you see a cheetah lounging near an antelope in one of these spots. Even after she died, her staff alone managed to generate spontaneous flora and the same peaceful-type area. Also, it was able to force lesser undead to stay away, and make greater undead really uncomfortable near it.) After getting the staff, you can return to one of her enchanted places and face down the Faerie Queen. Doing this gives you access to the Resistance spell, which drastically reduces ALL magic damage done to you, and really costs nothing because of the staff itself being a veritable fountain of magic. So, this is actually TWO examples, the Staff and Resistance, which turns a Wizard into an engine of death (more so than previously, at least).
 * Drakengard has a strange example of this for its Final Boss fight. While being deeply symbolic of the protagonist's embodiment of humanity as a whole, it is mind-bogglingly impossible to describe how this conflict would take place in any world other than that of Platonic Forms or similar realms of higher existence. The symbolism is the reality, which leaves one clawing out their own eyes wondering where the reality is.
 * In Age of Mythology, the ever-withholding Zeus finally hands down a blessing to Arkantos that makes him a demigod in, yes, the Final Boss scenario. Seems a lot more could have been accomplished by doing this earlier. Comes with free strange godly garb.
 * Well, you had to make a Wonder before this happened, so maybe Zeus needs Wonders Badly?... because . Yeah, that was the best I could do.
 * Maybe the gods have rules about interfering and gambit in that last scenario allowed Zeus to retaliate within the rules? Maybe heroes aren't supposed to get godly powers until they really need them?
 * Well, this is Greek Mythology we are talking about. If any setting must work within the rules of Drama, it's this one...
 * In God Hand, the player begins the game as Gene, having just had his dismembered arm replaced by the God Hand, an arm formerly belonging to a mythical fighter who originally defeated the Demon King Angra. ) Finally, after that event, you learn (for the final fight only) the Double Shaolin technique. It's the most powerful attack in the entire game.
 * In Legacy of Kain: Soul Reaver 2, you happen to be awarded the game world's ultimate weapon just before the final boss rush. This weapon isn't just extrememly powerful, but also makes you invincible, thereby turning what you'd think would be a tough climactic battle into a series of pretty mindless smackdowns.
 * This, in addition to the fact that there really aren't any boss fights in the game, just reinforces the idea that Lo K:SR2 is just a giant cut scene.
 * The Legacy of Kain games seem fond of this. Blood Omen 2 and Defiance both equipped you with the fully powered Soul Reaver for the end battle. It was, needless to say, utterly destructive.
 * Defiance actually does it twice.
 * In Paper Mario, the Peach Beam, which you can't defeat Bowser without, is granted halfway through the final boss battle. What's more, the game doesn't allow you to keep playing after beating the boss, instead returning you to your last save point.
 * Don't forget about Paper Mario: The Thousand-Year Door.
 * Played straight with the Shadow Queen. Halfway through the battle, Mario's Crystal Stars go out to all over the world, and the various people they've met all give their support to him, causing the Shadow Queen to lose her invincibility.
 * In MOTHER (predecessor to EarthBound, also known as MOTHER 1 and Earthbound Zero by fans) the final boss is toppled by
 * Earthbound's final boss was killed in a similar manner, where
 * The massive stat boost that Ness gets at the end of the Magicant level also counts as this.
 * In Secret of Mana, you didn't get access to the true power of the sword until you fight the final boss. One thing that was interesting is that the game leaves a gap in the spell lists of the Girl and Sprite and also doesn't allow you to upgrade to tier nine sword with the orbs, meaning that one could figure out something was going to happen if they stopped and thought about it a little (Dryad explicitly says that Thanatos sealed her 'Mana' magic).
 * Of course, using a glitch, the player is entirely able to get an extra orb for the sword and create the Mana Sword, which then becomes a Game Breaker in and of itself.
 * In Chronicles of Riddick: Escape from Butcher Bay, after spending the entire game using stealth and the occasional small-arms shootout to make your way through the prison, the final level grants you access to a Giant, heavily armored walking tank.
 * In Halo 3's climactic (not) final confrontation for the fate of the galaxy, you're automatically given a Spartan Laser, which coincidentally is the only weapon capable of harming your opponent (while the weapon is occasionally available as a regular weapon earlier in the game, the fact you get it out of nowhere, absolutely must use it to win, and are even treated to a cutscene of your character being completely owned without it, seems to make it an Eleventh Hour Superpower).
 * It is one. If you kill Johnson, and take the Spartan Laser before entering the area, you can have two Spartan Lasers for the battle (the first will only have a charge for one shot), but only the one you get in that cutscene is effective. So, not only do you get a Spartan Laser out of nowhere, you get the only one (well, sort of...it isn't the same as the one you took from Johnson the first time when you killed him) which is effective.
 * Psychonauts' Eleventh Hour Superpower is a crackling field of psychic energy that allows you to grow to monstrous size, given to you by
 * Condemned 2's Eleventh Hour Superpower is
 * In Aquaria, the Eleventh Hour Superpower was the character's final form, given just before the final boss:
 * Interesting in that you can stop the boss fight between the second and third forms and go off to do other stuff - but Celia apparently doesn't feel like stopping time anywhere else.
 * In the original Jak and Daxter, at the very tail end of the final battle with Gol and Maia's giant robot, all four benevolent forms of Eco combine to form Light Eco, the only substance that can completely negate the Dark Eco threatening to subsume the world. Once that happens, the entire remainder of the battle consists of simply getting to the stuff while the ground vanishes and the robot begins firing wildly at you and enemies attack from all directions. Since it seems to give you the abilities of all the other Eco combined and boosted, along with invincibility, the game just throws you into the end cutscene as the Curb Stomp Kill ensues. In short: once you grab it, you win.
 * Harbinger-possessed Collectors start dropping heavy weapon ammo in the final fight of Mass Effect 2, which makes the whole thing massively easier.
 * The "anti-god" enhancements to your weapons in the Penny Arcade game On The Rain-Slick Precipice of Darkness: Episode 1. More or less justified since the characters specifically sought out something which would allow them to defeat a god, but this doesn't explain why your weapons were also ten times as powerful against ordinary Mooks...
 * Would you want to be punched in the face with  Or make raked in the face with   Rain-Slick Precipice takes plenty of Refuge in Audacity, but the second game runs things a little straighter, with a more gradual increase in weapon power.   Refuge in Audacity, Turned Up to Eleven.
 * The final boss of Freshly-Picked: Tingle's Rosy Rupeeland sees Tingle use all the rupees he has collected in the game to power himself up so he can fly and shoot rupees. If all the rupee goods have been collected in the game a power up will also be activated boosting Tingle's stats and turning his suit Pink.
 * Appears during the final battle against Cynder in the rebooted The Legend of Spyro: A New Beginning videogame. You were given an immense purple fury which threw heads shaped like Spyro at your opponent until she fell down. Granted it was pretty cool, and you weren't Immortal while using it.
 * At the end of Eternal Darkness: Sanity's Requiem, you have to defeat the main enemy, Pious the Lich, as well as the dark god that the player chose at the beginning of the game while playing as Pious. You, as Alex Roivas, defeat them by
 * Another Eleventh Hour Superpower is essentially an Infinity+1 Sword that can only be obtained by collecting and placing various figures at certain chapters throughout the game. Alex Roivas collects it at the beginning of the final chapter. It's permanently enchanted, plus it can be thrown at enemies (making it an infinite-ammo ranged weapon since it reappears in her hands shortly after).
 * In Final Fantasy VII, if by the very last battle you don't have the Limit Break Omnislash yet,
 * Perhaps the coolest part about that battle is that, using the in-game explanation of Limit Break being the result of increasing anger,
 * Metal Gear Solid 2: Sons of Liberty has the High-Frequency Blade, a katana-like blade that slices enemies up and can even block bullets. The catch? You don't get it until almost at the end of the game, when.
 * Trauma Center has a strange one. At the end of the final operation, your 'Healing Touch' (which seemingly slows down time) automatically activates, as it has in operations before. The twist? If you haven't used it yet, you can use your use-anytime HT as well on top of the scripted one, and stop time. This is the only way to win.
 * In the sequel, New Blood, your time-slow Healing Touch gets upgraded to stop time in the last part of the final operation (where it is again needed to win). This is not explained. Or mentioned. Or even noticeable most of the time, since the final boss spends most of the window you have to activate it standing still. But it happens.
 * The final level of Crysis, your suit gains the (plot-dependent) ability to short out the alien drones, and you get a nuclear grenade launcher, both expressly for the purpose of taking down the final boss. You're not even allowed to use the cannon on anything else. It is available in Multi-player as a Doomsday Weapon, though.
 * The Expansion Pack Crysis Warhead lets you grab an absolutely overpowered plasma rifle that can one shot a heavy tank, something nothing else can do except the demo charges. However, it's not required to kill the final boss (since the thing is vulnerable to other weapons), but it makes killing it both easier (because of its ridiculously high firepower) and harder (very limited range, it's not a sniper rifle), as well as extremely fun.
 * It will also compel you to shout Get some! as you rip through the enemies you've been running from for hours. This will cause confusion for those in the adjacent room.
 * In Crysis 2, the last 3 levels have most of the MIKE maser guns found in the game, which is good news considering the fact that every alien in Manhattan is out to get you as you're . The suit also gain the ability to , which is how you win.
 * The expansion pack Sin: Wages of Sin similarly gave you a nuclear rocket launcher at the end of the game, although you were free to use it on anything you wanted (but you were probably better off saving it for the final boss).
 * The final level of Unreal II the Awakening gave you a gun that shoots black holes, which pretty much suck up and kill any enemy they even come close to. This weapon is the only thing that can kill the game's final boss monsters (whom it dispatches in one shot), but they're also armed with one, and can do the same to you. This weapon is so overpowered that a hit from an enemy will kill you even if you have god mode turned on.
 * In Persona 3, during the final confrontation, the Main Character draws power from all the people he's helped throughout the game, giving him the power of the Universe Arcana. Then the other team members give their encouragement, powering up a final attack that saves the day.
 * The protagonist of Persona 4 does the same against the final boss of the True Ending.
 * In a New Game+, you can actually fuse as a normal Persona. He's about as powerful as you'd expect.
 * Final Fantasy VIII: You can draw a magic called Apocalypse from the final boss's final form. This magic isn't available anywhere else in the game (hence you can't Junction it; hacking it shows that it works better than practically anything) but can be used for some major damage, as it's one of the only abilities which goes above the normal damage limit of 9999.
 * Chrono Cross: The eponymous "Chrono Cross" is actually an optional Element you can only get near the end of the game. Although it does refill your used Elements under certain circumstances, its main use is to get the good ending when used against the final boss, which also completely bypasses the final final boss fight.
 * It's also used in a special spot to combine party members from other saves.
 * Kingdom of Loathing: The final part of the final boss needs a special object in your inventory, the Wand of Nagamar. It takes the boss's powerful spells, and changes the way they work by turning them into anagrams. When you get this far, you can't lose.
 * It should be noted that the Wand of Nagamar (Nagamar is an anagram of... well, Anagram, for those who hadn't figured it out yet) is practically useless outside of that particular fight due to it's abysmal power; a mere 40 out of a possible 200. This can actually make it hard for non-combat classes such as the Sauceror and Pastamancer to progress in the initial two stages of the boss fight due to having to rely on their spells - which may not always work - and having no real melee power as backup with which to finish off the stages.
 * This has been changed, though - now you don't have to actually equip the wand, you just have to have it in your inventory.
 * Facing your Nemesis' final form turns your Legendary Epic Weapon (which by this time is obsolete) into your Ultimate Legendary Epic Weapon, with it's own Ultimate Special Attack. It's only 11th Hour in terms of that questline, though—defeating the Nemesis leaves you with the weapon and special attack, both of which are gamebreakers for the remainder of the main questline.
 * Mega Man X 5 hides the although you can technically start with them by using built-in cheat codes at the character select.
 * The first Mega Man X has Zero give you his Arm Cannon in the final stage, which upgrades your blaster significantly. Of course, experienced players will be well aware that you can find this upgrade (and several others) much earlier, but it's nice that the game gives you a freebie if you didn't find it before.
 * In X3 you can get the golden armor (upgrading all your armor parts at once) and Zero's saber near the end of the game.
 * In Mega Man Battle Network, gets a special update just after losing to The Dragon in the end, making it possible to win. Technically you probably could win without it, though.
 * In Tomb Raider: Legend, you It's used only to.
 * In Underworld you acquire  several levels before the end, and get to use it to wreak godlike havoc on enemies, be they simple gun-toting humans, sharks in water(!) or the various thralls
 * In Homeworld: Cataclysm, the manual says something easily forgettable about your fighter designs (which were traded to you) having their original weaponry replaced by standard guns as the designs didn't work. In the last mission you get the corrected plans - and find out that your standard fighters now use ion cannons, which are usually mounted on capital ships.
 * In SaGa 3 the only way to actually damage Xagor is to have the 4 Mystic Swords; magic helps but the swords are the only weapons that will actually deal physical damage to him.
 * The World Ends With You has a strange example of this occurring mid-game. Joshua gains a powered-up attack at the very end of the fifth day of his week. You get two days with his powered up form. This sounds longer than it is - a "day" is essentially a "chapter" in the game, and the final two days are relatively short and constrained to a relatively small area. After they're up, Joshua and his superpowered form leave until after you complete the game.
 * There is another, straight version of this trope applied during the final boss battle. During this battle, you're forced to fight alone. However, at regular intervals throughout the fight, an Action Command will appear on the top of the screen, healing you and boosting your attack power. Once you get the bosses health low enough, a gigantic Fusion Pin appears on the screen, allowing you to use your Fusion Attack with all three partners at once. While this "Quad Fusion Attack" merely serves as a flashy ending, it does reinforce the whole Power of Friendship theme.
 * The final level of Gears of War 2 puts you in the pilot seat of a . Suffice it to say, from that point on everything that gets in your way dies really quickly
 * Both Soul Blazer and Illusion of Gaia have a Phoenix based projectile, only unlocked in the last area, and the only way to damage the final boss. However Soul Blazer does unlock it in the middle of the last zone, and you can leave, and use it in previous areas.
 * The last mission of Hostile Waters gives you the Vulture, a quick, cheap, heavily armed air unit. Unfortunately, it is utterly useless in that particular mission.
 * At the end of Chelsea's part in Bunny Must Die, Chelsea fights Dechronos's second form. The player then starts playing as Bunny wearing a new gold bunny suit which makes her automatically parry any attack and gives an ability to throw big fragging swords.
 * Justified in that Bunny was body-jacked by Dechronos just moments before said Hopeless Boss Fight, as Bunny only has the gold suit in the battle against her and this final battle - and nowhere else in the game. Dechronos really should have known better than to use for his mortal vessel (however temporary) a character who is aware of him and had every intent to shut him down.
 * The Naruto movies are big fans of this trope as Naruto combines his Rasengan with some other form of power through unexplained or convoluted means to create a brand new version of the Rasengan to defeat the film's Big Bad.
 * Mind you, those new Rasengan are never spoken of again after their use.
 * In the strategy game Warhammer Fantasy Battle: Mark of Chaos and its novelization, both playable sides get this: The chaos champion transforms into a Daemon Prince after obtaining the MacGuffin while the Empire protagonist is given back his family's title of Elector Count, which carries with it access to a cool rune sword and the imperial menagerie containing a rideable griffon. In the game, the placement of both are more Sword of Plot Advancement with a full chapter remaining while the novel had them used only for the last battle (especially the griffon).
 * Before the final mission of Superhero League of Hoboken, Toastbuster and Zaniac join the party. Toastbuster has the highest Brawn in the game, and Zaniac comes with the insanely powerful Power of Confusion.
 * In the final mission of Pokémon Ranger: Shadows of Almia, you are given the Vatonage Styler, which allows you to befriend any Pokemon, even if it has been hypnotized by Gigaremo Units. This is an Eleventh Hour Superpower because there are no Gigaremo Units in the game after this mission is completed. Also, you cannot even damage the final boss until said Vatonage Styler is further upgraded by fusing with the Tears of the Princes. There is no use for this gem power outside of the final boss fight, so enjoy the pretty animation while you can.
 * There are many boss fights and quest-related events in World of Warcraft that give your character a temporary (and occasionally massive) increase in power, which is generally required to overcome the challenge in question. Specific examples:
 * One of the earliest examples occurs in Blackwing Lair with Vaelastrasz, a corrupted, fully-grown red dragon capable of wiping the floor with you and your friends. Fortunately, he wants to be killed and so gives the raid a buff that enables everyone to go crazy with maximum damage output for three minutes.
 * Kael'thas in Tempest keep (not to be confused with his weakened Magister's Terrace version) also does this—the fight begins with him sending his four advisers at you one at a time. After killing them, their weapons spring to life, and killing them allows the entire raid to loot them to temporarily use as Infinity Plus One Swords, which are necessary in order to handle fighting all four of the aforementioned advisers at once and kill them before Kael'thas himself finally decides to start attacking you. The weapons in question fade after 15 minutes or when you leave the zone, but after the dungeon was changed to not require killing the first three bosses in order to fight Kael, a bored guild took these weapons to one of the earlier bosses and beat her down in record time.
 * Kil'jaeden in Sunwell Plateau is another example - at certain points in the fight some of your characters can turn into dragons which can shield your group from his ultimate attack and breathe on them to drastically increase their attack and casting speed or regenerate large amounts of their health and mana.
 * Towards the end of the Death Knight starting quest chain when you are taking part in the assault on Light's Hope Chapel, your character is given higher health and damage output among other things in order to compete with the Elite mob enemies at the Chapel.
 * Likewise when you have to defeat Patchwerk back in Acherus almost immediately afterwards.
 * Much the same thing occurred during the now unavailable Battle for the Undercity -quest—if you were an Alliance player, you got to be escorted by Varian Wrynn; while if you were with the Horde, you got to run with Thrall—in either case, you got a HUGE buff to your health, damage, and healing that turned you into an unstoppable one man army.
 * The Ulduar raid dungeon features some bosses whose mechanics involve powering up the raid. The first is Hodir, a frost giant whose room comes prestocked with frozen allies that you can thaw out to get some nice buffs, which are necessary for most groups to kill him within the time limit. It's taken to the ultimate conclusion in the Final Boss fight with Yogg-Saron, in which you can choose to be assisted by any or all of the four bosses you freed from its Mind Control earlier. They buff the raid's health, damage, healing, and damage resistance; however, you will gain more loot and bragging rights for killing him with the help of fewer Keepers. "One light in the darkness" indeed.
 * At the end of the final boss encounter in Throne of the Tides, Neptulon buffs the party with PURE WATER, giving ridiculously high health and power to everyone, which you need in order to defeat the kraken Ozumat.
 * Similarly, each class has a special skill available for the fight against Shiro Tagachi, final boss of Guild Wars: Factions. The skill temporarily replaces one of your other 8 skills, is lost when you enter a town or outpost, and is very good. Also, you're gonna need it.
 * In Crystalis, only seconds before the final boss do you merge your elemental swords together into the eponymous blade, which, amongst having the attack power needed to defeat the final boss, also allows you to shoot out giant orbs of power at any time, essentially turning the final boss into a shoot-em-up game.
 * The first two Valkyrie Profile games do this. In the first's best ending, Lenneth is the only one who can do any significant damage to the Final Boss because she creates the sword Glance Reviver before the fight. This also gives her access to the full version of her Limit Break. In Silmeria, this happens when, and again, only she can do any significant damage to the final boss, though there is apparently a hidden scene only shown if you slog through the battle without her.
 * Covenant of the Plume, however, only gives it to you for the worst of the three normal endings. In the best ending, you don't get a special sword, but you do get a Guest Star Party Member.
 * Final Fantasy Crystal Chronicles does this with Ultracite. Only available during the very final boss, automatically casts Firaga, Blizzaga, Thundaga, Curaga, or a brief period of Invincibility.
 * Crystal Bearers does it too. When Big Bad  goes One-Winged Angel, it inadvertently activates a Super Mode for Layle, which lets him sky surf as well as greatly increases his powers.
 * In Vay, right before you head to The Very Definitely Final Dungeon, all of the elemental orbs combine with the pieces of Vay Armor you've found to allow it to be used to its full potential. It's the only weapon capable of dealing significant damage to the Final Boss (as even PJ's Megablast and Inferno spells will barely scratch him), and reduces all magical damage against the hero to 25%. Simply put, if he gets killed at any point during the battle and you don't have a Phoenix Heart or Lifestone handy, consider yourself boned.
 * Unusually for the genre, the shmup RefleX has one in the final two stages: when fighting the Raiwat Virgo, a Humongous Mecha that has been totally owning everything else in the game up to this point, your ship is destroyed when hit with More Dakka than its shields and armor can handle. For some reason (the story explains it, but the story is in Japanese...) your ship suddenly gains glowing wing things and a reflection shield with infinite power. The rest of the fight is you owning the Virgo, as only one of its super-powered attacks can even harm you now (so long as you keep the shield up). You keep this upgrade when fighting Raiwat Libra and two Kamui fighters in the Very Definitely Final Stage.
 * Sadly it does have a vicious twist. The No-Holds-Barred Beatdown delivered by the boss kill's the pilot and when she is dead the ships AI kicks in and activates the ships full power.
 * Billy Hatcher and the Giant Egg gives you the ''Light Ball' (which apprently stems from the Courage Emblems you've been collecting), and allows Billy to turn the Shadow Balls that Dark Raven shoots at him into 'Light Balls', which can be used like regular eggs, and is the only thing that can make Dark Raven vulnerable to damage.
 * City of Villains has one for each character class in the Barracuda Strike Force. The 5th Column's leader Reichsman is completely and utterly invincible thanks to the effects of a machine that takes energy from others and siphons it into him. The heroes defeat him in the Dr. Kahn Task Force by making a gun to nullify the effects of the machine. The villains instead round up the four Arachnos Patrons by lying to Lord Recluse, throw them in there, and siphon the power of the Patrons themselves into the team so they can stand against and strike down Reichsman. In addition to defense and damage buffs, Brutes gain an immunity to the effect that causes Reichsman to be near lethal in close-quarters combat, Corruptors get the ability to summon devils, Dominators get the ability to keep the entire room bar the team and Reichsman still, Stalkers get access to the swith that kills all of Reichsman's minions, and Masterminds can switch off Reichsman's invincibility. If you lack any of them, you're in for a tough fight.
 * In Terra's final battle of Kingdom Hearts: Birth By Sleep...
 * Also Aqua gets the game's best Keyblade in
 * Plus for the final battle of the prologue section of Kingdom Hearts II. Roxas gets to dual wield keyblades for the final showdown with Axel. It plays like Sora's drive version, except without the limited duration.
 * Also in Kingdom Hearts: 358/2 Days, on the 358th day, Roxas gains the ability to wield two keyblades at once. Shame it's only for a few screens.
 * In fact, you can't even use on the final boss due to Roxas giving said boss one of his keyblades before the battle!
 * The second half of Nox is completely dedicated to assembling the ultra-powerful Staff of Oblivion and yet you only get to use it against Hecubah and a few Mook.
 * Ironically, although the Staff does effortlessly vacuum up Hecubah's mooks, it's actually only modestly effective against her (despite the whole point of assembling it being to have a weapon capable of defeating her). Instead its best use seems to be stunning her for a second so you can hit her with a heavy spell like Fireball or Hand of Fate.
 * In the last level of BioShock (series) 2 you get the final plasmid, which is rightfully described as "It's Bring Your Daughter to Work Day". You're the strongest and most powerful thing in all of Rapture, and Eleanor is just like Daddy. Together you can just plow through about everything the city has to throw at you.
 * In Star Control 2 you receive a fleet of ridiculously powerful battleships free of charge just before you venture into the final battle.
 * On the flip side, your main ship - which you can build into an even more ridiculously powerful badass of a ship before that point - gets neutered into near uselessness at the same time. Considering that the main ship, when fully specialized for combat, is more powerful than all twelve of your other ships put together, this is actually a downgrade if you ignore the one-shot plot weapon added to the main ship.
 * In Magical Girl Lyrical Nanoha A's Portable: The Battle of Aces, Reinforce's final fight against Material-D is greatly simplified by
 * In BlazBlue: Continuum Shift, the Arcade Mode's final battle is against Hazama/Terumi. As Ragna, you get Blood Kain always-on without its life-loss effects.
 * Ragna's Azure Grimoire (the source of said powerup) in general. It's permanently grafted into his arm, but he seldom uses it. It's seen in action only in the aforementioned Terumi battle, his final battle with Unlimited Hakumen and Nu in Calamity Trigger's true ending, and as a probably non-canon Bonus Boss in Calamity Trigger arcade mode. Why he dislikes using it is yet to be revealed.
 * CS's story mode reveals why:
 * In SaGa 2 aka Final Fantasy Legend 2, your world's Crystal Dragon Jesus joins your party for the final dungeon. Her stats are completely maxed out and she's got the best attacks in the game. However, she leaves just before you fight the (very tough) final boss.
 * If you get a new mecha in the last few stages of a Super Robot Wars game, expect it to be a total gamebreaker. Here are a few, the from the last stage of SRW Z,  in Impact and in OG 2, and in the good ending of Alpha 3,
 * At the second-to-last stage of OG Gaiden, Raul rescues his companions, who board the Excellence Lightning. And start acting as subpilots for the Lightning. It carries over into the final stage as well. Well-upgraded, Raul can practically solo the last two stages after this event.
 * Alpha Gaiden offers although it is downgraded from  self, its pretty much the best unit in the game. It has high HP and Armor, not so bad mobility(which isnt really needed), nice set of weapons, and EN and HP regeneration L making it pretty much unkillable. Considering the game is pretty Nintendo Hard, its isnt enough to solo the remaining stages alone, but getting  makes the True Final Boss fight against  much more easier.
 * In Fahrenheit, Lucas Kane gains implausible martial arts skills just as he's being held up by several police officers. Granted, this happens at a point that's equivalent to the Disc One Final Dungeon.
 * Sudeki does this too. After collecting the people or your own realm and their darkness counterparts, you set for the final boss battle. Before engaging him, the characters fuse with each their darkness counterparts to become complete and overly powerful, but you only get to play one full character out of the remaining four. The others are parted by a barrier.
 * In Final Fantasy X after beating the final forms of, another series of battles starts up to eventually show the True Final Boss. Because the Fayth as a whole want this to happen, they aid you by giving your characters a permanent Auto-Life - the only way to die is to suicide by stoning.
 * In Wild ARMs 2, the protagonist's Super Mode is powered by a demon sealed away hundreds of years ago combined with the holy sword used to seal it away. The final battle occurs after the demon breaks free, leaving only the sword that the protagonist was unable to draw at the beginning of the game. One World of Cardboard Speech later, he's blasting the demon with Combined Energy Attacks in his new "Hero of the Sword" form while the rest of humanity makes speeches about not leaving him to fight alone.
 * In Scott Pilgrim's Finest Hour, the title character gets one in the form of a sword called "the Power of Understanding", after realising that he and the Big Bad Gideon are Not So Different. Natural, due to the heavy video game influences.
 * Not just that, but in the video game adaptation, you get the obscenely-powerful Power of Love Sword in the final stage of the game, and you only have it for fighting the penultimate boss. Luckilly, there's a cheat code that allows you to use it throughout the entire game.
 * In Wing Commander: Privateer, as you're headed towards an ambush planned by the navy for the Steltek drone that was following you the whole game, a Steltek ship appears and offers to upgrade the (already super-powerful) Stelkek gun you've found earlier. You can decline, but it's unwise, since the upgrade is the only thing capable of even making a dent in the drone's shields.(The whole navy taken into account)
 * In the Wii version of A Boy and His Blob you get the Instant Awesome, Just Add Mecha jellybean right after . Because you can easily trample over all enemies with it you only use it in the last two levels.
 * In Fine Structure, Ching absorbs the power of the Big Good just in time for the Final Battle with the Big Bad.
 * In Dragon Age: Origins, you gain the ability to call upon reinforcements during the It helps even the odds in the Final Battle since the Final Boss is summoning its own reinforcements too. In Awakening, you can activate Tevinter Towers in the final dungeon that will grant you several one shot combat abilities such as mass healing, mass stun, and a damaging fire blast that are only available during the Final Battle.   will also grant you an even more powerful fire attack aptly named "Cataclysm".
 * In the sixth scenario of Radical Dreamers a previously found jewel enables Serge to summon a giant to fight against Lynx's
 * Just before the Final Boss of Bionic Commando: Rearmed, you get the Bazooka upgrade, which allows you to freely control its shots. However, you can keep playing after beating the game and use this weapon everywhere else.
 * In Purple, you get Final Frisbee right before you fight final bosses enlargened form.
 * In Fable I, you get an Infinity+1 Sword - two variations with the different flavor but same function depending on allignment - at the end of core story. It is pretty much guaranteed to be your main weapon throughout the short and brutal Lost Chapters.
 * In Rogue Galaxy, the main character Jaster gets a glowy power aura of strength and a BFS with infinite reach to defeat the final form of the True Final Boss.
 * He also gets this with his fight with Seed and another person in the desert town, only minus the BFS.
 * In EverQuest II, this trope is in full force in the Vasty Deep: The Vestigal Cella zone. The boss of the zone can summon her elite guard who can one shot most people. If you burn her slowly though, a dragon who you fought before will fly in and imbue you with the power of the seas, massively increasing your health and your damage to fight off the elite guard.
 * Might and Magic VII gives you blaster guns for your final two missions, the latter of which will upgrade you to BFGs. It's a considerable upgrade from the swords, daggers, and staves you'd been using up to that point.
 * VI does something similar (the third mission from the end is all about getting blasters, but the second-to-last mission is non-combat and rather short), with the addition that blasters are actually necessary to win the game, rather than just very, very useful. Of course, in both games you might want to go off and get a few more levels (for the skill points necessary to get better at hitting with your new 'superpower') before continuing with the main story, and it is entirely possible to have much of the game left after getting the blasters (the games do not end after the main quest does, and there are plenty of side-quests).
 * Fallout 3 has the Tesla Cannon from the Broken Steel DLC, an incredibly powerful shoulder-fired electric cannon that uses only one Electron Charge Pack, one of the most common ammo types, per shot. The earliest you can obtain it is at the final battle against the Enclave at Adams Air Force Base. Where it will be incredibly useful, given the insane number of Power Armor-wearing Enclave personnel there. And unlike "Take It Back!" from the core game, you have to fight them by yourself, with no Liberty Prime or Lyons' Pride backing you up.
 * Secret of Evermore has the Energize power, granted via Call Bead near the end of the game: It allows you to use Charged Attacks instantly. With a fully-leveled sword, you can basically do Link's spin attack over and over again.
 * In Iji, the Massacre, which is obtained after completing a successful pacifist run.
 * Infamous 2 has this in the second-to-last story mission. A thunderstorm moves in when the mission begins, allowing Cole to draw power from the storm itself, allowing the player to recharge anywhere.
 * Played straight and averted in the Deus Ex series:
 * Highly averted in the original game, as most of the high-damage weapons can be obtained early on. The rocket launcher (GEP Gun) can be received in the first level. The plasma gun is obtained roughly a third of the way through the game (in a military base). The best melee weapon is found roughly halfway through the game. The only problem is finding the space to store all of them.
 * In Deus Ex: Human Revolution, the Plasma Rifle is only received after fighting the second-last boss.
 * In Sin, the experimental fusion pulse rifle can only be obtained three levels from the endgame, and requires the assembly of several different pieces (the first of which is obtained very early in the game). Somewhat toyed with; while it is a deadly weapon in its own right, and is capable of killing most enemies from that point on with a couple shots, it won't do much good against the final boss.
 * The battering ram from Bastion, although due to its limited range and slow attack speed you might wish you could just use your normal weapons instead.
 * Demon's Souls, of all possible games, gives you this in the Shrine of Storms, to avoid forcing an effective game restart for any melee-focused character. Against the Storm Ruler, the final boss of this world, make a dash for the abandoned Stormruler sword, and you'll be throwing Razor Wind around like so much candy. It's strong enough to be superior to the innate damage potential of most ranged or magical characters, making it a weapon of choice for them as well, and to avoid balance issues, it loses most of its power outside of the Storm Ruler's domain. Not, of course, that an Infinity+1 Sword will make this boss easy...it's still not that kind of game.
 * Order of Ecclesia gives you a glyph that allows unlimited flight... halfway through the final area. To be fair, you can use it in one of the bonus dungeons. The one that's entirely focused on combat.
 * Warhammer Online has the Lost Vale, one of the hardest PVE raid areas in the game. The final boss, N'Kari, is a terror - but this is offset by colored orbs floating in the arena that increase your DPS, healing or hit points to crazy levels for a short time. Just make sure they pick up the right ones - having your ranged attackers gain a truckload of hit points, your healers get a buff to damage dealing and your tanks become very good at healing is not good.
 * Asura's Wrath
 * Perfect Dark: It's not in the last level, but the RCP-120 comes at just the right moment in the hardest level in the game for Joanna Dark to grab it, activate the Invisibility Cloak and sneak past a dozen guards to defuse a bomb before it destroys the Institute.
 * In MS Saga: A New Dawn, it's both the the Nu Gundam and the Sazabi.
 * For the vast majority of Monster Girl Quest, Luka has to fight on his own, barring a brief segment where he has a far weaker ally. In the final dungeon, Alice fights alongside him starting from halfway through the first fight, automatically attacking after Luka takes his turn. In the final stage of the final boss fight, the Four Heavenly Knights and Micaela all join the fight as well, albeit only one at a time. Said fight is also the only fight in the game where the enemy will attack allies, rather than focus on Luka exclusively.
 * For the final battle in Lust Grimm, will, over the course of several turns, massively buff your stats, give you a powerful offensive skill, and debuff the boss.
 * In Battle Golfer Yui, Yui learns the Black Fire skill before she faces off against her final opponent. It's a combination of the Kamaitachi, D. Marionette, and Aquahopper skills.
 * For the vast majority of Monster Girl Quest, Luka has to fight on his own, barring a brief segment where he has a far weaker ally. In the final dungeon, Alice fights alongside him starting from halfway through the first fight, automatically attacking after Luka takes his turn. In the final stage of the final boss fight, the Four Heavenly Knights and Micaela all join the fight as well, albeit only one at a time. Said fight is also the only fight in the game where the enemy will attack allies, rather than focus on Luka exclusively.
 * For the final battle in Lust Grimm, will, over the course of several turns, massively buff your stats, give you a powerful offensive skill, and debuff the boss.
 * In Battle Golfer Yui, Yui learns the Black Fire skill before she faces off against her final opponent. It's a combination of the Kamaitachi, D. Marionette, and Aquahopper skills.

Anime and Manga

 * In the final episode of the first Tenchi Muyo! Ryo-Ohki OVA, the titular character was able to summon the Light-Hawk Wings (something that normally couldn't be done except by special trees. No, really) to defeat Kagato where no one else could. In a later episode of the extended OVA, he was able to do it once more to rescue two of the girls from a black hole.
 * Tenchi is a fan of this. In the TV series, Ayeka manages to tap Jurai Energy (an energy that only the royal family can access, but Ayeka never did) to shatter her bonds and send a death wave at Kagato. Unfortunately, Kagato is immune to Jurai Energy and sends the attack back. However, Tenchi then busts out Jurai Energy and combines it with Earth Energy to defeat Kagato with the power of trees, neither of which he had access to because he was still learning the nature of his power.
 * In the first movie, when Tenchi's mother realizes who Tenchi is, and thus what she is, she instantly gains access to all of her latent powers and kicks the Big Bad's ass long enough for everybody to escape.
 * In the second movie, when Tenchi is trapped in the dark world and unable to access his light-based powers, Ayeka uses a branch from her brother's tree-ship to project herself (and a source of light) into the dark world, granting Tenchi the ability to use his standard light-powered sword-based baddassery. This functions as a double case as both Ayeka used a never-before-seen power, and catapulted Tenchi to new levels of power.
 * Right before the final battle of the second season of Magical Girl Lyrical Nanoha, Chrono receives the Durandal, a powerful Storage Device that was able to freeze a huge, bio-mechanical Eldritch Abomination along with a large chunk of the sea surrounding it.
 * Mermaid Melody Pichi Pichi Pitch: KODOU (which in the second season was reduced to a practically first-level song) and Kibou no Kaneoto -Love goes on-.
 * In Kamichama Karin, Micchi's mysterious transformation ring isn't activated until towards the end of the final battle.
 * Digimon Adventure: Almost every Big Bad was defeated this way - Devimon through Takeru and Patamon learning to evolve at literally the last second, Etemon through Taichi and Agumon activating his crest for the first time, Vamdemon through Hikari and Tailmon finishing becoming Sixth Rangers and again through two of the protagonists learning to reach the Ultimate level, and Piemon through Takeru and Patamon (again) activating his crest for the first time; the last being the straightest example in that it took place at the climax of the third-last episode. This does tend to be something of a recurring tendency across the franchise as a whole in how new evolutions are obtained - at practically the last second when fighting a powerful enemy. As the series went by, when dealing with a Big Bad it only happened once or so per series and restricted themselves to dealing with the actual biggest Big Bad; these being Dukemon Crimson Mode, Susanoomon, ShineGreymon Burst Mode and Shoutmon X7 Superior Mode.
 * The third part of JoJo's Bizarre Adventure features Star Platinum, Kujo Jotaro's Stand, who has a very short range so it should be very powerful... but he only seems to have an outstanding speed, great strength and surprising sight and precision.
 * Dragonball Z: Super Saiyans, firstly done by Goku in attempt to beat Frieza, and the other is pulled by Gohan in attempt to beat Cell. Both involves the bad guys doing something to trigger the heroes' ultimate anger. Both persons debut real SSJ 1 and 2 into the main series.
 * In the anime version of Yu Yu Hakusho, Yusuke, after recovering from a mid-battle Heroic BSOD against Yomi and regaining a purpose in life, temporarily achieves, which provides enough of a power boost to fight one of the most powerful demons alive to a near draw, Yomi only winning by passing out mere seconds after Yusuke.
 * Cosmo in Sonic X turned into a tree during the final battle with Dark Oak (granted this did ultimately cause her death and is supposed to be a general thing for her species - her growth spurt was just sped up a bit by a magical amulet).
 * The Miracle Lights in Pretty Cure All Stars acts like this, granting the gathered teams their Super forms to flatten that movie's Big Bad.
 * These sorts of things had been going on since the first Futari wa Pretty Cure Max Heart movie, just that the Yes! Pretty Cure 5 movie gave it something physical with the Miracle Lights.
 * Infinite Stratos has both this and Second-Hour Superpower. During his first battle, Ichika's Byakushiki achieves First Shift which essentially means the suit customized itself to him by reading his combat style. In the final episode, Ichika has Epiphany Therapy and the Byakushiki undergoes Second Shift, becoming Byakushiki Setsura just prior to entering the fray. Compared to its original form, the suit loses its Crippling Overspecialization for melee combat by supplementing Reiryaku Byakuya with a ranged attack and Deflector Shields.
 * Similarly, Houki was the most combat-ineffective character in the show due to not having a personal IS... until three episodes from the end when she got the Aka Tsubaki. didn't lie when she said it was powerful - that suit is a textbook example of a Lightning Bruiser.
 * In the anime GaoGaiGar, the organization GGG decides to finally activate its superweapon Goldion Crusher after all of their troops get beaten to a point just before death. This super weapon enables Genesic Gaogaigar to destroy the artificial sun, which was creating endless clones of the enemy Psycho Rangers. They actually had the weapon the entire time, but they were waiting to use it until the enemy sun made itself vulnerable by overextending its cloning abilities.
 * Puella Magi Madoka Magica deconstructs this trope (big surprise). Following the arrival of Walpurgisnacht, Madoka's hand is forced and she agrees to become a Magical Girl in order to save the day. It's too bad this is All According to Plan and will lead to Madoka's destruction (and also the destruction of the entire world). Homura continues to turn back time until she can keep her friend from powering up in order to save her life (and the planet).

Film

 * In Kamen Rider Double Forever, Double is getting his butt kicked by Kamen Rider Eternal when the people of the city start calling out to him, imbuing his normal Super Mode with the power of their hopes, turning Double gold and giving him wings.
 * In Tangled, it's revealed at the climax that Rapunzel's tears share the same power as her hair.
 * In Space Jam, Michael Jordan, despite playing like a regular basketball player most of the movie, suddenly develops, ironicly, a Looney Tunes style body at the final seconds of the Big Game. This is right after he witnesses his human friend Stan Podolak get flattened like a pancake and subsequently inflated like a balloon.
 * Bit of a subversion in that Michael could have done that at any time, he just didn't know that until the game was almost over.

Literature

 * The Deathly Hallows in Harry Potter and the Deathly Hallows. A trio of relics not even mentioned until halfway through the last book; where the final battle suddenly hinges on their existence.

Web Comics

 * In El Goonish Shive, this happens three times. One had to be justified later, another is justified in previous development and the last one was built up in more than two years so that it was bound to appear and could not be anything less than Summon "Oh Crap".
 * In MS Paint Adventures, pretty much everything that Problem Sleuth does after  counts here, ending with him

Western Animation

 * In the middle of the third season of Transformers Animated, Prowl picks up the ability to use "processor over matter", which is basically telekinesis.
 * In the second season finale of Ben 10: Alien Force, Azmith grants Ben the ability to control and transform into all the aliens in known existence in the Omnitrix (and there are a lot more than 10,000, by the way). He was able to transform without having to manually slap the switch down . The Omnitrix resets back to its original settings   It later comes to bite Ben in the ass when he and Kevin decide to hack it and get the same power in the upcoming fight with Vilgax in the new season...
 * In the second-to-last episode of Harley Quinn, Poison Ivy manages to tap the power at the source of the Green, causing her plant-manipulation powers to increase substantially, to the point where she can almost effortlessly terraform Gotham into a Garden of Evil. And she switches her regular clothing for a sexy garment made of leaves too.