Fighting Your Friend

""Have you been keeping well? Thank you for Mt. Coronet. I'm truly grateful. [...] The power you learned... I can feel it emanating from you. But that's enough talk. Let's get on with why you're here. As the Pokémon League Champion, I accept your challenge! There won't be any letup from me!""

- Champion Cynthia, Pokémon Diamond and Pearl

A Boss Battle in which you fight against a character who's explicitly on your side (otherwise it's Civil Warcraft or Let's You and Him Fight). Occasionally this is the Warmup Boss in which your ally decides to test your skills before you start your real mission. It can also be a form of Heroic Sacrifice in which the other good guy must die in order to accomplish a goal, and you have to be the one to do it. In some cases, your ally or allies are being mind-controlled or otherwise forced to fight you. Or maybe they have done a Face Heel Turn and have become evil. Occasionally, especially in Fighting Games, a character will beat up their friend to prevent them from fighting the Big Bad. Better a few lumps than getting killed.

There are a few situations in which this may become a case of That One Boss. An ally may be powered by the dark side or has to be fought one-on-one with either a specific character or the player character. In western RPGs about building individual character strength, no problem...you should be a Game Breaker by this point anyways. But in a Japanese RPG that emphasizes the strength of a group working together? Having only one ally might be quite a handicap without additional damage-dealers and tanks. Sure, in this case, the opponent may have reduced stats compared to a regular boss fight, but still almost always way more stats than they could ever actually attain while on your side to give the player a challenge. They'll also have their entire skillsets to throw at you, occasionally even more.

Contrast Defeat Means Friendship, in which case a villain becomes your ally because you fought it. Compare Tragic Monster, "I Know You're in There Somewhere" Fight. May involve a Trial by Friendly Fire.

WARNING: Some of these are a little detail heavy, so SPOILER alert.

"Yuri: You're not going to beat me in an argument. But you know what you can beat me in... (holding up his sword) This."
 * Several Final Fantasy games use this trope:
 * in Final Fantasy III. Especially annoying because it's a  even though they're ON YOUR SIDE!
 * in an optional series of fights in X-2.
 * in XII.
 * in IV as the mind control variant. also has to be fought, but the hook here is not to harm him.
 * Final Fantasy Tactics Advance has one battle where you have to fight in order to get to the final area of the game. She has no hard feelings against Marche, but just doesn't want him to progress any further.
 * Final Fantasy Tactics A2 does it again with
 * Hell, even in Dissidia Final Fantasy, Terra gets mind controlled into fighting one of the heroes, Cloud fights Firion to test the strength of his dream, WoL and Squall fight etc. It's not uncommon.
 * in Final Fantasy XII Revenant Wings. Making this worse is that it's probably the hardest fight in the game, and that the whole thing is a stupid misunderstanding.
 * The Nameless Mod features this in the WorldCorp storyline. You'll be forced to fight  And if you attempt to do the   ending on a WC playthrough, you'll get this with   if you have rekindled your relationship with her.
 * 2027 has this with  at the end of the game, or not, depending on your choices.
 * Done very well in Mega Man X 5, with X vs. Zero. It helps that there are actually 3 possible intros to the fight, depending on who you're playing as and It also helps that the ending of one of the previous games hinted that something like this would happen.
 * Mega Man Star Force also does this, as in the first game Geo is forced to fight Bud, Sonia and Luna when they are tricked by the evil FM-Ians (Taurus, Lyra and Ophiuca), into getting revenge against people who wronged them (i.e. Vaughn and Veil Platz for Luna, her (Luna) and Geo for Bud and Chrys Golds for Sonia). Then in the second game as both Bud and Luna are taken over by what Omega-Xis calls residual energy and then as Vega and Hollow trick Sonia into doing their dirty work for them. Finally in the third game as Taurus becomes corrupted by the bad guys and is forced to merge with Bud as a result of it.
 * Julius in Castlevania: Aria of Sorrow.
 * Trevor Belmont in Curse Of Darkness too.
 * in Castlevania: Symphony of the Night.
 * In Dragon Age Origins, you have to fight Wynne and Leliana if you choose to despoil the Urn of Sacred Ashes while they are in your party.
 * You will also have to fight Wynne if you choose to ally yourself with the templars.
 * In Atlus's Digital Devil Saga,
 * In the sequel  Subverted in that
 * The Magic Knight Rayearth SNES game featured a sequence where one of the trio had to fight the other two. This is one of the last variety, where the other guys are being mind-controlled, and in fact, you're supposed to lose; if you kill them, you get a game over. This is actually made kind of hard, or at least boring, by the fact that their AI is utterly crappy and it can take forever for them to kill you with their piss-weak attacks.
 * The same case happened in the anime: in one episode, Hikaru and Umi were Brainwashed and Crazy thanks to the still not Heel Face Turned Caldina, therefore Fuu had to fight and disable them on her own.
 * Happens a bit in Tactics Ogre. You are guaranteed to fight Vice at least once in the game (The reasons differ, though, between him making a Face Heel Turn or accidentally getting caught in a bad spot), Leonard often fights you, Guildus is reanimated into a death knight, and in one path, Denim's sister Kachua is so angry at you she actually stays behind in the fight against Lans Tartare!! (In other chapters, Lans tells her to run away and she obliges.)
 * Tactics Ogre's Gaiden Game, The Knight of Lodis also does this. In Path A, Orson is fought, and then Rictor is possessed, making you fight him twice. But in Path B, Rictor is only fought once and it is instead Cybil who is possessed by the Big Bad. The first Rictor battle happens regardless of path choice, as does the battle with the mermaid Aerial.
 * In Yu-Gi-Oh!: Nightmare Troubadour, one section of the game pits you against a mind-controlled Joey. Winning or losing this battle results in a Game Over, so you have to use particular cards to make the game end in a draw. (This comes straight from the series, though it had a different explanation.)
 * In Blue Dragon, when you encounter Marumaro for the first time, he will fight you to prevent you from interfering with his quest for medicine for his village.
 * The Super Famicom game Tenchi Muyo! Game Hen has everyone's favorite Space Pirate Ryoko Hakubi as a late-game boss, following her abuction by the Big Bad halfway through the story. It's a bit of a subversion in that defeating Ryoko earns the player a Game Over; the object of the mission is to defeat the Ryoko clones (easily identifiable as recolors of the real one]] who are acting as the real one's flunkies.
 * Xenogears uses this trope several times too. There's only three party members you don't fight at some point in the story.
 * Advance Wars: Dual Strike features a disturbing version of this, in which potential allies pit their armies against yours in order to test your skills as a commander. If you follow the story from the perspective that the game's units represent actual human soldiers, it's actually rather horrifying.
 * From the first Advance Wars there's Rivals!, a secret mission you can get if you use a certain CO on specific missions. It's the same.
 * Alternatively, it's just like modern military exercises. Just ignore the explosions. Heck, it could even be a computer simulation.
 * In the first dungeon of Fallout 2, the main character must fight a fellow tribesman to display his worthiness. If you're smart enough, you can opt to talk your way out instead.
 * Performed spectacularly in Chrono Cross. After defeating Lynx atop Fort Dragonia, Serge is At that point, your friends and   attack you and you must defend yourself. The odd part is, you're actually given the chance to win (but what kind of heartless monster would beat his own friends into a pulp?) The outcome of the battle is the same whether you win or lose, however.
 * Arguably, battling the Dragon God (the fusion of the Six Dragons) is one such battle, since.
 * The major boss fights (against Trinity and Seraph) in Enter the Matrix are like this. The former is a sparring match between friends. In the latter case... he fights EVERYONE he meets with, apparently.
 * Done pretty well in Tales of Vesperia: until Yuri offers him a way to make his point: a swordfight.

": I can't even win with a sword anymore. Yuri: (teasingly) Hahaha... Loser."
 * The two then proceed to trash-talk each other while beating each other up. They feel better afterwards, but

"We're in a hell of a business, old buddy! Nothing's ever what it seems!"
 * Yuri also fights in an "I Know You're in There Somewhere" Fight.
 * The Play Station 3 version adds several more opportunities to fight your friends, most notably
 * Also in the arena Karol (in a poor disguise and loudly claiming not to be Karol) will fight alongside his Hunting Blades guildmates if he's not in your current party. In addtion
 * Happens in every Tales (series) game, actually, with the exception of Tales of Eternia and Tales of Phantasia. Oftentimes it gives a nice battle?
 * Unless you count fighting the Summon Spirits.
 * Which is Defeat Means Friendship.
 * Well, Tales of Eternia does pit you up against
 * Tales of the Abyss also does it the least since the only friend you fight is Asch...No one's sudden betrayals actually result in a battle.
 * Tales of Rebirth goes crazy with this trope. In Tales of Rebirth, you fight (Unless you count the training battle)
 * Like Tales of Rebirth, Tales of Symphonia also has a little too much fun with this trope...but not to the point described above.
 * The Sequel includes a possible final battle but this is one where you're supposed to lose, Winning results in the Downer Ending.
 * Depending on the team you choose in Touhou Imperishable Night, stage four will have you pitted against Reimu or Marisa. This is also where the difficulty level of the game spikes dramatically.
 * This also happened earlier in the series, in Lotus Land Story, with Reimu and Marisa being pitted against each other in the fourth stage.
 * In Ten Desires, the Stage 1 boss is, who here is just helping out the heroines and holding back her power to serve as a Warmup Boss.
 * The third stage of Magical Battle Arena has your character finding her respective ally (Nanoha and Fate, Sarara and Kirara, Lina and Naga) only for the rules of the universe forcing them to fight to get out of their current area. The only ones that doesn't are Sakura and Kukuri, who instead invokes Defeat Means Friendship on each other for the team battle on the next stage, and Ruru and Nowel, who will go through said team battle solo.
 * A variant occurs in Paper Mario: The Thousand-Year Door. One boss fight has you fighting a traditional boss but your allies are fighting alongside him.
 * Also, Mario is forced to fight
 * A subversion of this occurs in Bayonetta where it's revealed that Jeanne, who is fought on multiple occasions, is actually the protagonist's brainwashed childhood friend.
 * Happens The Legend of Zelda: Twilight Princess, wherein you must fight
 * And once more in Phantom Hourglass, in which the final boss is actually.
 * In Soul Calibur II, an odd version happens in both Kilik and Xianghua's story modes. While the majority of characters fight against their enemies, these two fight because they don't want the other to go on to face Inferno and potentially be killed.
 * And to a lesser extent in the same game, Seong Mi-Na defeats Yun Seong because it's "no place for kids." Presumably she's thinking of herself in terms of the Christmas Cake definition of "old".
 * World of Warcraft has several. Vaelestrasz in BWL tries to beat the main boss before you get there and loses, gets partially mind controlled so he has to fight you and is weakened throughout. Considering how tough he is, it's a wonder Nefarian managed to beat him, really...
 * Kalecgos, the first boss of Sunwell Plateau is a blue dragon who tried the same thing. His will is stronger or something, because you beat him by killing the monster possessing him. His ally, the third boss Felmyst was not so lucky, probably because she is some sort of undead monster by that point.
 * Keristrasza! I'm noticing a pattern here. Dragons don't seem to have very much luck when they try doing our job or helping us, do they?
 * Indeed, by this point about half of the dragons fought in the game are former allies. Sapphiron and Nightbane may also count, being reanimated dragons.
 * Thorim and his proto-drake (again, basically a dragon) in Ulduar. Also Freya, Hodir.
 * Saurfang Jr. is turned into a boss in Icecrown
 * Persona 3 FES:
 * Baldurs Gate II. Fellow escapee and very charming thief Yoshimo has no choice but to go apeshit half way trough the game because of an unbreakable Geas oath. So yeah.) and fight with the PC. He doesn't get better, though you can deliver his heart to his church to give him some forgiveness in death.
 * In The World Ends With You, you finally fight the Conductor, who
 * Melty Blood occasionally has the Back Alley Alliance of Satsuki and Sion fighting each other to prevent the other from getting killed.
 * Resident Evil 5 features a boss fight where Chris and Sheva end up fighting
 * Castle Crashers has this happen if you're in a multiplayer game. After rescuing a princess, the players fight to the last man to decide who gets to kiss her. Even though you can brutally cut down the other players, everyone will start the next level alive and well.
 * In one of the Metal Slug games, one of the characters that you did not choose is under mind control and fights you. They can use the same weapons you can, switch them at will, and can use their melee weapons just like you can. Defeating the creature controlling the character frees the victim.
 * That was Metal Slug 6. This also happens (sort of) in 3, where your character is abducted by aliens and you have to play as a different one to recover them. Along you way you fight legions of clones of the captured character.
 * Happens fairly often, usually via Mind Control, in the Super Robot Wars series.
 * In Super Robot Wars Original Generations, this has tallied up quite a lot. Brainwashed and Crazy victims include Kusuha (twice, by and ODE), Excellen (twice too! By, and Einsts, especially Alfimi) and Lamia (twice in the same game: first ODE, then Duminuss), and the rest of the ODE victims. The first game, however, pits you against Sanger (who's been fighting with you for the first few stages) in a convoluted plot of Stealth Mentor.
 * In Chapter 10 of Super Robot Wars MX, Duke Fleed in UFO Robo Grendizer has to to fight Great Mazinger (piloted by Blacki) and Mazinger Z piloted by a brainwashed Kouji Kabuto. Eventually, he breaks Kouji free and defeats Great Mazinger with his help.
 * Metal Gear Solid has a number of these.
 * In Metal Gear Solid Snake has to kill  a second time.
 * During the battle with Psycho Mantis, Snake has to fight without delivering a killing blow. If that person dies, you get a Nonstandard Game Over.
 * And of the Ac!d spin-off series, a fight with.
 * Kingdom Hearts does this a few times actually with Riku. He is first evil and is jealous of you, then attacks, and the next time he's possessed by darkness and becomes That One Boss for several players.
 * 358/2 days also does this even more.
 * Aqua has to fight
 * In the C path of Valkyrie Profile: Covenant of the Plume,
 * Xenosaga stayed away from this trope until Episode III when.
 * The final battle of Mother 3 is a great example of this, in which
 * The battles against  in Metroid Prime 3 definitely count. They all help you at various points through the game, and in the 75% ending, Samus mourns their deaths.
 * In the final battle in Beyond Good & Evil, the Big Bad possesses (and clones) Jade's friends, complete with mind fuck. ("It's your fault we're suffering!")
 * In the Chicago History Museum mission in Stranglehold,

""I didn't want to have to do this... but neither of us have a choice, do we...?""
 * This becomes more and more the case with Pokémon League Champions through the first four "generations" of games. In Red/Blue, it's your Jerkass Rival. In Gold/Silver, you have Lance, who is on the side of Good Is Not Nice and is all "I see potential in you; now I'll try to utterly crush you to see if I'm right". In Ruby/Sapphire you have Steven who's pretty much your chum. Then in Diamond/Pearl you have Cynthia, the do-gooder Adventurer Archaeologist who wants to be your BFF, helps you save the world and wants you to know this whole battling-you thing is tremendously fun for her. Then in Black/White you have Alder, a kindly old man who walks the earth, does his best to give you a hand and has the most festive and upbeat battle theme ever. At this rate it won't be long before we have a game where the League Champion is a Care Bear.
 * While your rivals in the first two generations of the game are both Jerkasses, May/Brendan, Wally, Barry, Cheren, and Bianca are all considerably friendlier.
 * Street Fighter has indulged in this trope more than a few times, most prominently in Street Fighter Alpha 3 and (Super) Street Fighter IV's Rival Battles.
 * Alpha 3: Bison abducts Ryu and injects him with a portion of his Psycho Power, forcing Sagat to try and rouse him out of this as Ken and Sakura face Bison. Also, the Bushin Ninja Guy tries to reach out to his best friend Cody, who has gone from the hero of Metro City to an apathetic, snarky, fight-addicted brooder, as he believes that deep down, Cody still holds some goodness in his heart.
 * IV: Rose believes that Ryu is The Chosen One destined to defeat Bison, but doesn't want him to preemptively rush into danger (according to her visions, he can vanquish Bison only at a specific time). On the other end, Guy tries to prevent Rose from facing Bison herself because while she intends to eradicate (or at least stall) Bison, she has seemingly resigned herself to death and holds a far greater importance to the world than she believes (he tried this before in Alpha 3 but failed, leading Rose to eventually be possessed by Bison in the interim between Alpha 3 and II; it should be noted that he and Rose were not True Companions at this point). Cue battle (and some unintentional Ship Tease). He also confronts Cody again, mainly for the same reasons as their fight several years prior, as well as trying to convince Cody to join him in the fight against Seth and S.I.N.
 * Fate/stay night, Heaven's Feel route. Shirou vs  Made worse by the fact that to play Heaven's Feel, you have to have played the Fate route in which
 * Agarest Senki has Valeria fighting against you in the 2nd generation when Ladius runs away from his enemies, forcing two childhood friends to fight against each other.
 * In Agarest Senki 2, this happens twice in the entire game. It happens first with  The second one only happens if one goes to the Bad Ending and that is
 * In Shiren the Wanderer 3, Shiren and Asuka fight because Sensei disagreed with her. Even if you have Shiren say that Asuka's right, the fight happens anyway (and Sensei backs out of the fight, which Koppa calls him out for) So, basically, they're fighting because they had Sensei as a boss, so why not Asuka?
 * The penultimate fight of Story Mode in Mortal Kombat 9 is It doesn't end well. It also happens a bit earlier in Kitana's chapter, where she duels her servant Jade (the latter having been sent by Shao Kahn to keep an eye on Kitana). This fight isn't nearly as emotionally heartwrenching
 * Like any other fighting game worth its salt, BlazBlue has cases of this. The above quote is a lampshade by Makoto, who was forced into fighting Tsubaki just to keep her from killing Noel. She even went out of her way to forge an order to withdraw just to avoid hurting Tsubaki herself, and the fighting was pretty much a last resort.


 * The Dragon of Neverwinter Nights 2 will try to convince some of your party members to join him and the Big Bad against you. If you fail Influence checks with these characters, they will be swayed. Special mention goes to Qara and Sand: their rivalry means it is literally impossible to keep one without having the other turn on you.