"This is a big veiny sword with a creepy, blinky red eye in it. The kind of thing that, when you look at it, you say 'Okay, yeah, I'm pretty sure that sword is evil, and probably cursed to boot.' It looks totally badass though, and hits like a mofo. And I think we can all agree that that's a reasonable trade-off."
Obviously, weapons are made to hurt and kill. These weapons enjoy it too. And some will try to talk the wielder into it, with strange voices of all kinds. Some are heard with the ears, some sound in the mind.
These weapons might kill everything in their way, rather than just what they need to. Some refuse to go back into the scabbard without killing. Some just don't activate the awesome magic without the wielder killing a kitten. Some kill not the body, but the soul. Some kill their wielders as well, whether directly or indirectly, instantly if they're hungry enough or over time by draining Life Energy. Some don't. Because, you see, they wield the wielder, instead of the other way around. And they are prone to being hard to get rid of.
How did they come to be like that? Some were deliberately enchanted, or rather cursed. Some are imbued with the evil of their maker, some indeed, are the Soul Jar of an evil human, if not something even worse. With some, it's the material they were made of, and some were corrupted by deeds done with them, even worse than the usual cruelty of the battlefield. Some may be Forged by the Gods - but not by any of the nice ones. If It Was a Gift—do not trust the giver thereafter.
The "personality" of the evil weapon often varies according to the traits associated with it. A dagger is insidious, an axe encourages brutality, staffs are subtle and sophisticated in their corruption... Swords are the most common evil weapon. Most other weapons have a peaceful purpose: bows and spears for hunting, hammers for hitting nails, axes for chopping wood... The sword and mace are the only medieval weapons that cannot serve any purpose except war. Because they are so common they also vary much more in how they are evil.
- The swords made by the man who made Kenshin's sword were all like this, save for his last two.
- In this case the swords weren't evil in and of themselves, they were just more likely to attract bloodthirsty users due to the way they were made.
- Inuyasha has Tokijin, forged from the fangs of Goshinki, the monster that broke Inuyasha's sword Tessaiga. The completed sword is infused with Goshinki's power and malice, to the point that Tokijin actually possesses its maker right after he forged it. It later tries to do the same to Sesshomaru—but Sesshomaru is so badass that he suppresses Tokijin's power completely with his own, after which it causes no more trouble.
- Slayers has a few examples. The anime has a cursed knife, which Lina attempts to pawn off to an unfortunate shopkeeper. The novels have Doolgofa, the Cursed Sword of Bezeld, which is actually a disguised mazoku who will fuse with any poor fool who picks it up.
- In Slayers Try the Sword of Light is revealed to be another dimension's Dark Lord equivalent—and there are four others just like it.
- The Weapons of Light -- at least those in the regular Slayers universe and not the sentient starships of the Lost Universe alternate universe are a bit of a subversion, however, in that they don't seem to possess any sort of will of their own, nor do they influence their users in any way, excepting possibly giving them an opportunity to go mad with power. In fact, they were used as intergral components of the spell to destroy their creator, with no resistence or side effects on their part.
- In Slayers Try the Sword of Light is revealed to be another dimension's Dark Lord equivalent—and there are four others just like it.
- Love Hina had an evil katana that possessed Naru, Keitaro and a monkey. Played mostly for comedy.
- Then it showed up in Mahou Sensei Negima. Not played for comedy (much).
- Anubis in JoJo's Bizarre Adventure is a sword with its own Stand, which possesses whoever picks it up. Even a piece of it has this effect.
- Soul Eater has demon weapons, the evil counterpart to the Shinigami's Death Scythes. Both are good and evil in their own right. The main difference being the latter powered themselves up by eating corrupted souls and the former were more indiscriminate.
- The Nakatsukasas' fey blade seem to be one of these; corrupted, possesses the wielder and destroys their soul...but can be turned to good use with the right influences. Apparently many, many previous members of the family had missed out on the last part before Tsubaki decided to have a meister in Black Star (probably significant she was the first of the family to have a meister, given this is a series that favours Loners being Evil.
- The Anathema Scythe from Tetragrammaton Labyrinth. At one point it was described as enjoying the pain it inflicted on it's wielder; it was so evil it was able to convince an Angel, a being that by definition does not know death, that it had been murdered. The source of its power, and root of its evil is the nail from the Crucifixion that was used in its construction.
- In My-HiME, Mikoto's sword Miroku is an aspect of a very malevolent demonic entity, and it rarely ever leaves her sight because Mikoto's family had trained her to use it ever since she was little, and it and the pendant she wears possess mind-controlling powers.
- In One Piece Zoro gets a cursed katana. It encourages the owner to seek conflict and kill, but Zoro was able to overpower it. Occasionally it delivers a serious blow when Zoro tries to hold back, like on Whiskey Peak. It is not sentient, nor does it ever "communicate" in any way- we only have Zoro's reactions and sense to go on.
- It's also the youngest, and thus weakest, of three swords of the same class by it's forger. The oldest is also said to be in the strongest category of swords, and is likely to be much more evil.
- Sacrifar, the ninth form of the Rave Master's Ten Commandments sword, is actually a subversion. When Haru used it, it increased his bloodlust and tried to forcefully merge with his body, causing Musica to wonder why his grandfather had created the sword with such a form. The answer: He hadn't. What the elder Musica had done was create a sword for the specific use of Haru's predecessor which, in its more powerful forms, would not work properly, if at all, when Haru himself tried to use them.
- The Decologue, Lucia's sword, is a more straight example. As a Dark Bring, it constantly tries to corrupt its wielder, and since Lucia's other Dark Bring turned out to be sentient, it's not too great a leap of faith to think that the sword might be as well.
- Cards that can corrupt, brainwash, possess, harm, or kill their wielder are a common occurrence in the Yu-Gi-Oh!-verse, such as:
- The Seal of Orichalcos during the Doma Arc
- Hell Kaiser's Dark Cyber Deck in Yu-Gi-Oh! GX Though Shou gets a good grip on it later.
- Recently in Durarara!!, the truth of the cause of the Slasher attacks was caused by a group of mind-controlled crazies around town, courtesy of a sword called Saika, which wants to love, but cannot do so properly, therefore attacks people to "love." The true sword of Saika is revealed to be inside Anri Sonohara.
- In a Bleach anime filler arc only appearance there are the Bakkōtō swords that - unlike Zanpakutō who are borne of their users souls - are more akin to parasites that will become increasingly powerful with their wielder, but also devour their user eventually. They're outlawed for that very reason.
- Miramoto Musashi's bokken from Ranma ½.
- In The Warlord, Machiste found an ancient cursed axe containing a demonic entity which took possession of his mind. The demon's will prevented Machiste from letting go of the axe. Seeing that the axe's influence was making Machiste more and more tyrannical as well as violent, Travis was forced to remove his friend's right hand, thus severing the axe's spell.
- The Ebony Blade, sword of The Avengers member the Black Knight, was afflicted with a blood curse due to all the blood the original Black Knight had spilled. Dane Whitman eventually purged the Blade of its curse at Doctor Strange's behest by plunging it into the Brazier of Truth while Strange bathed them both in magic fire. The curse returned, however, when the Sub-Mariner used it to kill his wife Marrina. The curse seems to affect different people in different ways. It turned Dane into a statue, it amplified Proctor's gann'josin-based powers, and it granted Sean Dolan great physical powers as Bloodwraith.
- Carvin' Marvin from Knights of the Dinner Table.
- In an early Transformers comic. Megatron is damaged and becomes stuck in gun mode with no free will. A petty criminal picks up the super-powerful gun and uses it to become a highly successful criminal, but the experience ends up pretty much ruining his life anyway. To cap it all off, after screwing up the crook's life beyond repair, the gun wakes up, turns into a giant robot, insults him, and leaves.
- Blackfire in With Strings Attached. It's a bit of a Stormbringer Expy. The four hate it when the Hunter first displays it, and realize it's evil when they see the very similar Heart of Evil. In fact, it's so obviously evil that they're a bit startled when the Hunter claims it's not. When he asks to accompany them back to C'hou so he can give up his adventurous life, they point out that the natives (at least the skahs) have no concept of good or evil, and if he brings Blackfire with him they'll learn what evil is. (Though John mutters that the skahs “might not mind.”)
- In the movie Asoka, Asoka's grandfather tells him to put his sword away because it's a demon that desires bloodshed.
- The crystal sword Alanna gets after Lightning breaks in The Woman who Rides Like a Man actively tries to kill whoever uses it. Alanna eventually masters it, but it refuses to obey her once in the vicinity of its maker, Duke Roger
- Michael Moorcock's Stormbringer (from the Elric stories and others) actually steals people's souls in order to give its wielder strength - including those of many of Elric's friends as well as his enemies. And Elric's. Turns out the sword is actually a demon.
- The Hand of Kryll and Eye of Rhynn from Moorcock's "Swords" trilogy are also...morally questionable. The eye allows you to see into a Limbo-like world of pain and shadows. The hand allows you to summon the creatures of this realm who kill everything in their path. These victims then take their place in the purgatorial world until they are summoned, or else spend eternity in torment. Fairly evil. The fact that even creatures who were fearful pacifists in life are motivated to become remorseless (and effectively invincible) killing machines by this realm should be a hint that it's not Disneyland in there. Differing timescales with the 'real' world, a la Narnia, are implied.
- Another is The Cold Sword, a blade which "personifies" Evil Is Deathly Cold. It's implied to be an alternate universe Incarnation of Stormbringer. While it doesn't consume souls, as far as we know, it's still far from a friendly sword. Though it does save the world on it's own accord at the end of the story.
- The Gonne in in Terry Pratchett's Men at Arms, which wasn't just a powerful weapon, but a weapon that could possess the mind of those who hold it, tempting it with the power it has and what the holder could do with it.
- The three titular swords of Tad Williams' Memory, Sorrow, and Thorn are Empathic Weapons with a twist: they can control their wielders against their will. However, the most fitting example of this trope is Sorrow, forged and wielded by the Storm King prior to his death. Merely touching it can freeze you or destroy your soul.
- The other two swords, Minneyar and Thorn, aren't exactly evil (though they are unnerving if you're not used to them), but the fact that they want to come together and be used alongside Sorrow makes it possible for the Storm King to use them as his tools anyway.
- In Graham McNeill's Warhammer 40,000 Horus Heresy novel Fulgrim, Fulgrim's Chaos-tainted sword. It lures him into treachery and murder and when he fights his own brother, Ferrus Manus, convinced him that he must kill him to save his life. Then it plays on his guilt and lets him realize the full extent of it, and uses that to persuade him to let it possess him.
- Morganti weapons in Dragaera destroy/devour the souls of their victims, and Vlad could sense the hunger in one he was attacked with, and felt one he used to threaten a villain trying to turn in his hand and kill. This semi-sentience is downplayed later on, as Vlad isn't up close and personal with them that often. The Great Weapons are Morganti as well, but are more versatile and don't have to destroy souls (once even being used to store Aliera's, allowing her to play possum by actually being fatally wounded.)
- While a lot of the Great Weapons are shown as loving and protective toward their owners, a story set in the universe titled "The Desecrator" shows this trope to be totally straight with Telnan's Great Weapon, Nightslayer. Nightslayer is basically a Captain Ersatz of Stormbringer and is described being pure evil and wanting to slaughter everyone and everything. Telnan seems to have more luck than Elric in controlling such a weapon, convincing it that if it travels with him, it will have plenty of killing opportunities.
- The Infernal Devices were three super-kick-ass blades from Simon R. Green's Blue Moon Rising. Subverted a bit, in that these ultra-powerful, ultra-Eeeevil weapons nevertheless fail to get the job done.
- The Speaking Gun from the Nightside novels, made out of meat, and capable of unmaking anything by speaking its name in reverse. Created to kill angels, but hateful and eager to kill anything.
- Khazid'hea was picked up by Drizzt Do'Urden and used by Catti-Brie, the sword could slice through rock with relative ease and spoke to the mind of the wielder to increase their blood lust.
- Subverted with the sentient sword Nightblood from Warbreaker. Though very powerful and incredibly dangerous to anyone in the vicinty, it was actually created for the purpose of destroying evil. Problem was, the Awakener who created it didn't realize that a sword has no conception of human morality, so Nightblood continually goads its wielder into trying to kill everyone in sight, just to be on the safe side.
- The "thirsty sword" in The Remarkable Journey of Prince Jen is quite possibly Axe Crazy as well as evil. It can talk, but all it ever says is "More drink," by which it apparently means blood. Prolonged use turns a rebel leader into a Complete Monster.
- The sword Excalibur in Bring Me The Head Of Prince Charming. After the eponymous prince takes it off a Black Knight, he finds that the sword is utterly paranoid and Ax Crazy, and tries to convince him to kill everyone he meets. After he leaves it in the forest, it tries to get revenge on him by siccing a group of demons on him.
- The four elemental swords The Secrets of the Immortal Nicholas Flamel. They absorb the memories of anything they cut, actively corrupt an unprotected user, eventually absorbing their souls, and so far in the series nothing has been introduced that they can't kill. Clarent (fire), the most evil of all of them, is the one the protagonists end up with for a while. Even the Eldritch Abominations are afraid of them.
- The short sword with the wavy black blade in Aaron Allston's Galatea in 2-D. Kevin designed it to be the sort of sword a devil would use, and it's capable of killing The Cape (trope).
- In L. Jagi Lamplighter's Prospero in Hell, the Wounding Wand. Caurus thinks he's too tired, because he hears it; Miranda warns him to not listen.
- The Dresden Files has the Blackstaff, a possibly living stave that massively amplifies the power of any act of black magic it's used in. In an inversion, however, the stave is used to prevent the wielder from getting corrupted; when Ebenezar McCoy uses it to kill hundreds of mercenaries in one go, the staff seems to absorb the darkness of the act rather than letting its corrupting influence affect the wizard.
- In Time Scout, whenever anyone brings a modern weapon downtime, its presentation is rather... dark in comparison to the works of art that art downtime weapons.
Live Action TV
- One episode of the Super Sentai series Mahou Sentai Magiranger featured the evil samurai Shichijuro, a Monster of the Week with a sword that could cut anything (including non-physical concepts like the bonds between the team.) Eventually, he's taken down, but the sword remains. When Magi Green picks it up, the armor of the monster appears around him and he attacks the others, revealing that the real Shichijuro was the sword, posessing its wielder. (Which, in hindsight, means the "monster" who just got Humongous Mecha-ed to death was probably a perfectly innocent whatever-he-was before touching the sword...)
- VR Troopers had the Millennium Saber. Fortunately, it only activates once every thousand years, hence the name. The rest of the time, it's old and rusty.
- Mighty Morphin Power Rangers has the Sword of Darkness, which Rita used to sustain her control over the Green Ranger. The name says it all. And it looked so awesome, too. Of course, the weapon on Power Rangers you most want to stay away from is the Dino Thunder White Ranger power gem, which drove its user mad. To be fair, that was after Mesagog had it soaking in evil energy for a long while. Once that was gone, the White Ranger was an okay guy.
- Discussed in NCIS with a certain handgun that has apparently been used in several unrelated crimes.
- The Lance of Longinus (a.k.a. "Spear of Destiny") in the short-lived TV series Roar.
- Kullervo from The Kalevala had a rather nasty sword that talked to him before his suicide. It also inspired Michael Moorcock and Tolkien.
- There is also an attempt by Ilmarinen to forge the Sampo, where a failed attempt results in:
From the fire arose a cross-bow,
With the brightness of the moonbeams,
Golden bow with tips of silver;
On the shaft was shining copper,
And the bow was strong and wondrous,
But alas! it was ill-natured,
Asking for a hero daily,
Two the heads it asked on feast-days.
- The swords made by the Real Life swordsmith Muramasa are sometimes portrayed like this. Anecdotes tell of him competing against his master Masamune to see who was the better swordsmith. They placed their swords in a river, to see if they could cut the passing leaves and fish without effort. Muramasa's swords cut everything indiscriminately, while Masamune's did not. A mark of their sharpness, yes, but also their complete lack of restraint or recognition of innocence.
- Norse Mythology features swords that can not be sheathed again without killing someone.
- The Ba'al Verzi daggers in the Ravenloft setting have borrowed that idea, or at least are rumored to.
- In Irish Mythology, Lugh's spear, variously called Luisne and Brionac, had the advantage of being able to fight on its own. The bad news: it wouldn't stop, not even when the battle was over. Solution: Immerse the spear's head in poppy juice, keeping it in Snoozeville until it was needed again.
- Dungeons & Dragons: there are every variety of magic swords that can be thought of, including swords that cause greater injuries if used against those of certain Character Alignment.
- Bonus points to the magic axe "Lifedrinker", which drains Life Energy from anything it hits, and half as much from the wielder at the same time, and to intelligent magic items in general, which come with an Ego score that scales with their power. If their Ego is substantially stronger than your Will save, they take over your body. Using a magic item with a similar alignment and goals can be an interesting choice, but often comes back to bite you. Using an intelligent evil weapon? Not so good...
- Several cursed katanas in Legend of the Five Rings RPG, including the blades such as Ambition (which does Exactly What It Says on the Tin and also is more deadly against those of higher position than the user.)
- Several in Warhammer Fantasy Battle and Warhammer 40,000. For starters, every single daemon weapon ever. Notable one's include Kingslayer, the sword of Archaeon, the Lord of End Times (Warhammer Fantasy), Gorechild, the chain-axe belonging to Kharn the Betrayer (40k), and Drach'nyen, the sword of Abaddon the Despoiler (40k). The Primarch Fulgrim in 40k got corrupted by a powerful daemon weapon. The weapon slowly caused him to turn to Chaos, and in the end, when he refused to obey it, it possessed his body, turning him into a daemon.
- There's a Khornate mace that drives its wielder to ever-higher states of bloodlust until the wielder finally collapses from exhaustion. And then it turns on its bearer, because Khorne cares not from where the blood flows...
"Willingly you picked me up. Your first mistake. Willingly you drew me. Your second mistake. I do not allow my servants to make three mistakes, foolish mortal..."
- Soulsteel weapons and armor in Exalted fit the bill—while they can technically be used for any purpose, including opposing evil, the soulsteel that composes them is exactly what it sounds like, and their bonuses work by draining the life and vigor out of their victims (in the case of weapons) and attackers (in the case of armor). Meanwhile, hell-forged weapons and armor may have still-living demons bound to them as part of their creation...
- One of the Deathlords favours a daiklave crafted from the soul of one of the few pure heroes of the Old Realm...who was driven violently insane as part of the forging process. In fact, a whole lot of Deathlords favor soulsteel weapons that work upon these principles; one soulsteel daiklaive will eat the soul of anything it slays, restoring a measure of its wielder's health.
- YuGiOh TCG: Word of God says the equip spell Wicked-Breaking Flamberge - Baou holds the dark power of Baou, its Gaurdian spirit. When Warrior Dai Grepher later wields it, he is overcome by the dark energy and later becomes Dark Grepher.
- The Soul Edge from the SoulBlade and Soul Calibur series. The Soul Calibur was an attempt by the former wielder (at the time) of the Soul Edge to create the exact opposite of the 'Sword of Destruction', that is, a Sword of Order. However, it apparently just winds up in the other extreme, in that the Soul Calibur wants nothing more than to freeze the entire world in crystalline perfection... where there will be no war, no death, no destruction... because nobody will be able to move.
- Which is interesting, because Soul Edge was a regular sword corrupted by countless kills on the battlefield, while Soul Calibur was forged from a piece of Soul Edge... Who would think that was a good idea?
- There are other lesser weapons in the Soul Series who are quite evil; Taki's Mekkimaru and Yoshimitsu's self-named sword are both evil swords with inmense evil power and destructive abilities. In Mekkimaru's case, it has even driven Taki's master insane by the time of the first Soul Calibur.
- Frostmourne of Warcraft III is one of these. It even corrupts the wielder (not that the wielder wasn't asking for it), and hungers for souls. It can drain the victim's soul to strengthen the wielder or to be later reanimated.
- In fact, all deathknight runeblades are sentient to a degree, and share a bond with their owner.
- Although this got shot to hell in World of Warcraft, when it turns out that a runeblade is made by taking any old stick and putting the runes on it yourself, with no indication of sentience.
- Another example from Warcraft is Atiesh, greatstaff of Medivh, the last Guardian. When Medivh got possessed by Sargeras, the creator of the Burning Legion, he sealed a powerful demon inside his staff, turning it into an evil weapon with terrifying magic powers. The staff was later shattered to prevent it from falling into evil hands, but in the lv.60 version of Naxxramas raid, players could acquire its pieces to remake it and then banish the demon, making it wieldable.
- Yet another example is the corrupted Ashbringer, also from the lv.60 version of Naxramas. Ashbringer was/is the exact opposite of this trope, being a sword made specifically to destroy any unholy beings, but after it's wielder got murdered by his son, it became corrupted. Players who wield the corrupted Ashbringer will occasionally hear the sword whisper to them in a creepy voice. In the Wrath of the Lich King expansion the sword got cleansed and is now wielded by Highlord Tirion Fordring, the leader of the Argent Crusade. It even shattered Frostmourne at the end.
- The Baldur's Gate series:
- The first game has the Cursed Sword of Berserking, one of the few +3 weapons in the first game. As the name suggests, the sword drives its wielder into berserker rages and cannot be unwielded except until the curse is removed. A hapless guard captain ruined his life when he unwittingly purchased the sword and slaughtered his own family.
- Lilarcor from Shadows of Amn is more insane than evil, but it sure does enjoy killing...
- There's also Blackrazor from SoA, a life-draining sword that's not intelligent for any practical purposes (it's just another weapon in game terms) but is very firmly described as evil. And the original game has Varscona (better known as "that longsword +2 you can get early in the game"), whose combat bonuses are explained as possibly deriving from its vaguely undead original owner merging with it after remaining entombed for centuries and developing "a rage that bordered on insanity".
- In Throne of Bhaal the Infinity Plus One Sinister Scimitar "Spectral Brand", when fully powered, is described as "an instrument of unholy death that should never have been unleashed upon the Realms".
- Bishamon in the Darkstalkers fighting game series is a samurai possessed by a demonic armour (Hannya) and sword (Kien, which roughly translates to "demonic flame"). Even after he manages to rid himself of these artifacts' influence, they somehow form a body out of nothing at all, allowing them to continue their killing sprees. All they ever talk about is slashing, blood and suffering. And they still go by the name Bishamon, possibly to spite their erstwhile host.
- Mike, Yoriko's
kittystaff in Arcana Heart which is a sealed Demon King in reality and is more likely to use Yoriko as a bludgeoning device than the other way around. Though really, he is more of a Jerk with a Heart of Gold Weapon than an outright Evil Weapon. Offer him enough doughnuts and you'll have a friend for life.
- Essentially all of the minions of Smithy in Super Mario RPG are this - except they're also sentient beings that want to ruin the world. Up to and including Exor, the massive sword that strikes Bowser's castle in the game's introduction. Smithy himself is something like this. Smithy himself is a demonic blacksmith that wants to replace all of the wishes in the world with weapons, and his minions are part of this plan.
- Kleever from Donkey Kong Country 2. It's apparently a posessed, evil sword that starts out being weilded by an arm made of fire, then just attacks on it's own accord. And looks like this
- While not actually evil, The Star Dragon Sword from Suikoden is an enormous asshole, and at one point tries to kill the party for being left in a cave. It was left in the cave because it was constantly complaining how much it hated it's wielder.
- Several games in the Mana series feature floating possessed swords as enemies.
- Evil Weapons in Final Fantasy XI are floating living weapons that possess the bodies of earth spirits to fight for them.
- Breath of Fire IV has a variant that qualifies as Nightmare Fuel in and of itself, being the Hex Cannon/Carronade. Per official documentation in the artbook, the Carronade not only poisons the land with curse energy but also simultaneously empowers and possesses its users.
- What makes the Carronade especially horrific is two different things—the first being the scale of the thing in that it is a literal Nuclear Weapons Expy and essentially the magical equivalent of multi-megaton nuclear ICBMs and the second being how the Evil Nuclear Weapons Expy is fueled: Specifically, persons with a connection with the target are tortured to the point insanity and hopelessness, and then are used in human sacrifices as the "warheads". If that wasn't creepy enough, the Evil Empire of the game specifically seeks out potential "warheads" based explicitly on the closeness of the connection between "warhead" and "target"--the Evil Weapon also specifically works under the theory Love Hurts, with the "best" ammo being a person in love with the target. Yes, you are reading that correctly: the Carronade is an Evil Weapon that is a magical method to Nuke'Em—and one which runs on Nightmare Fuel specifically operating on the fact Love Hurts.
- The Nox Nyctores of BlazBlue are immensely powerful, but amplify latent psychoses in their wielders.
- Not exactly evil, but very very insane, the soul of Raziel inside the Soul Reaver, which has been in said blade for thousands of years several times, kind of, and it feeds off the souls of it's slain.
- Some axes in Planescape: Torment are so evil they cannot even be held by good characters. Names like "Hatred Gift" (wielder goes berserk), "Butcherer of Innocents" (steals enemy's life points) "Edge of Oblivion" give a hint. Another one "Entropic Blade" is has no evil qualities of it's own and can be wielded by anyone without any repercussions, but in order to obtain it you have to unleash a powerful force of, expectedly, entropy and destruction on the universe which deed instantly turns you Chaotic Evil. That's a worthwhile trade-off for a powerful weapon, right?
- In Team Fortress 2 some of the unlockable weapons for the Demoman replace his normal Mad Bomber arsenal with a haunted Claymore (which lowers his health, but grants him bonus health if it's used to kill people) and shield. It also constantly whispers "headsss".
- And from the Halloween update we get a haunted battle axe, which is haunted with the spirit of the Horseless Headless Horsemann. (It has the exact same stats as the Eyelander, however.)
- There's also the Half-Zatochi. Not stated to be evil, but like the Norse mythology above, it can't be switched out unless you kill someone.
- Tales of Symphonia has the Devil's Arms, which are nine demonic, almost organic-looking and moving weapons that apparently can talk, although only Presea is able to hear them.
- The Masamune in Chrono Cross. Originally an Empathic Weapon, it was once stolen from the kingdom of Guardia and used for evil, turning the once holy sword into a demonic, warped blade that can corrupt or take over the mind of anyone who wields it. Destroyed by the sacred sword Einlanzer in the Home World, and cleansed of all evil influence in Another World, it was restored to its shining glory and transformed into the Mastermune.
- The Fire Emblem series has the Demon weapons, which are incredibly powerful, but can randomly make you take damage instead of your opponent.
- And then in Fire Emblem : Seisen no Keifu, you have the Demon Sword Mistoltin. Not an evil weapon in truth, as it's one of the Holy Weapons of the Twelve Crusaders which saved Jugdral from Dragon Evil Overlord Loptous : but it's a sword that craves for blood, as lampshaded by his 2nd Generation owner, Ares/Aless ; the Special Skill it grants (Critical) and the main stats boost it gives to its user (Skill, needed to activate Critical often) are another giveaway of this.
- The header description from Kingdom of Loathing doesn't mention how the Spirit Precipice takes its toll. On a critical hit:
A bolt of evil energy arcs out of Spirit Precipice and hits you in the [body part].
You lose 12-24 hit points.
- Dragon Fable has the Doom Weapons, which ostensibly exert a corrupting influence over their owners, although this has yet to manifest in any obvious way. It also features the Necrotic Blade of Doom, a much more straight-forward example complete with Evil Laugh, massive hamishness, a position on the Omniscient Council of Vagueness and obviously being the boss of the Big Bad. You can either wield them as-is, or you can have Artix purify them to turn them into Destiny Weapons.
- The PlayStation 2 remake of Shinobi has the main character wielding Akujiki, a cursed soul-eating sword that if not repeatedly fed, will begin to eat the wielder (in this case, main character Hotsuma)'s own soul.
- The bonus character's non-named sword also consumes the soul of his host, though it eats through its reserves rather fast, meaning you get much less leeway on platforming between combat segments before you start losing health.
- Magic sword "Makoto" from Demon´s Souls is in fact one of these, draining life from the user by each second it´s equipped. You can also turn any normal weapon into a Curse Weapon using a spell with that very same name.
- The cursed blade Yugiri in Bushido Blade corrupts whoever holds it. It's done this for a long time.
- In the epilogue of Dragon Age Awakening, it's heavily implied that Vigilance becomes one of these. Of course, it was forged with the bone of an ancient evil dragon (whose ghost you had to fight to get the bone) that lived in a swamp that bridged the gap between the physical world and the spiritual one. It would have been a surprise if the thing didn't turn evil.
- Dragon Age II: Near the end of the first act, an Artifact of Doom gets onto the market. Later, it is used to smith an Evil Sword, and makes Meredeth, who was already a Knight Templar, turn outright evil and crazy (and make her eyes glow red). She eventually tries to use it to become a One-Winged Angel, but that backfires, turning her and the sword to stone. Before that, it allowed her to use magic, including animating statues to fight for her.
- Enserric in Neverwinter Nights: Hordes of the Underdark is a vampiric weapon named after the wizard it killed. The wizard's soul became trapped in the blade and the weapon became sentient. Enserric will encourage you to wield it against as many foes as possible, though it will complain if it doesn't like the "taste" of certain foes (it doesn't like being used against undead, for example). You can also channel a fraction of your own lifeforce into the blade to make it more powerful.
- Magic Sword Maxwell, later more appropriately referred to as Demon Sword Maxwell, qualifies as this in .hack//GU Redemption. Infected with a particularly nasty AIDA, the sword puts anyone it "kills" into a coma in the real world and constantly demands to be "fed", but in return makes the wielder (hint: not you) practically invincible. Oh, and breaking the sword just frees the AIDA to infect Haseo.
- Strife featured The Sigil. Made by an evil god to corrupt the world, worshipped by its Evil Empire Cult, and burns the user's life force to power it.
- The Kris of Ashrah in Mortal Kombat: Deception, which Armageddon later explained is a sentient sword who fills its user with illusions of being purified as a way to make him/her slay his hatred enemies, those of the Vampire race.
- Tekken has Yoshimitsu's katana, likely the same one from Soul Calibur, which in Tekken 6 is revealed to drive its wielder crazy if it doesn't taste blood regularly.
- Desire in Eien no Aselia tries to force Yuuto to bend to its will through pain. What it wants is for Yuuto to rape, pillage and murder. Near the end it's revealed that it couldn't really help being like this because it was undergoing the equivalent of prolonged starvation. It also has a little bit of a soft spot.
- The Chaos Sword in Ultima V is arguably the most powerful weapon in the game, capable of killing virtually anything in a single hit. Also, using it in combat causes you to lose control of the character wielding it and cause him/her to attack fellow party members as well.
- Many weapons that do Spooky damage in Kingdom of Loathing. Several are made from human remains.
- The quest "ANIMUSLAVER!" in The Sims Medieval involves dealing with the titular sword. You eventually learn it's possessed by a demon that has already cleared out entire kingdoms of people through its wielders. Depending on the approach, you either guide a Knight and Spy in uncovering and ultimately destroying the blade (though the Knight becomes temporarily possessed by it), or letting a Jacoban Priest and a Blacksmith leverage the blade's evil for the good of the Jacoban Church.
- Zulwarn from Vanguard Bandits is a Humongous Mecha example. It is one of the most powerful ancient ATAC mecha, one with the power to Mind Control foes. Zulwarn also has a corrupting influence on anyone who is crazy enough to pilot it, though it's not so obvious when the pilot is already a Complete Monster of course. And unlike other ATAC mecha, Zulwarn doesn't rely on a powerstone—it is fueled by human blood.
- The Orchid Malevolence from Otogi: Myth of Demons is a crimson bladed sword covered in purple flames that can kill anything in one hit. The catch? It saps all of your health while it is held, turning you into a One-Hit-Point Wonder.
- The Muramasa legend above is brought back in the series Muramasa: The Demon Blade, where 108 swords are bound to Muramasa's spirit, and he is unable to pass on until they've all been crafted. The swords have various curses upon them in exchange for their power, as they cannot be put away until they've killed something, and corrupt the minds of unworthy or undisciplined individuals, culminating in the Kuzuryu sword corrupting and possessing the mind of the shogun, Tokugawa Tsunayoshi, with a dog demon trapped within.
- The Elder Scrolls games have at least two of these. Umbra from Morrowind and Oblivion is a powerful soul-stealing sword forged by an evil witch that twists its wielders into insane Blood Knights. In Oblivion, Barbas begs you not to deliver the sword to Clavicus Vile, since he believes even a Daedra Prince wouldn't be able to control the blade's evil power. He's right. And Umbra pales in comparison to Mephala's Ebony Blade in Skyrim which becomes stronger every time its wielder kills a friend or loved one with it. You need to kill ten trusted companions to fully empower the Ebony Blade. Other weapons in the games also have unsavory origins, but at least they don't corrupt their wielders or actively encourage them to be bastards.
- The Legend of Zelda: Skyward Sword has the sword of the Demon King Demise. It can take on the form of a white-haired man called Ghirahim, who has an Ax Crazy Blood Knight personality.
- Stormbringer from Nethack is a "bloodthirsty" sword. Normally, when you want to move onto a pet or peaceful monster, you don't attack it (you get confirmation for attack for peaceful monsters, and displace (swap places with) pets). While wielding Stormbringer, you attack those without confirmation.
- The second game in The darkness series introduces the sword Kusanagi, originally benevolent, an evil shogun used it to take thousands of innocent lives, corrupting it. In order to purify it, it has to be fed the hearts of (via impalement) ten thousand evil souls, or it reduces the lifespan of the current wielder by a year. Lucky for the sword, his current wielder is the revenge crazy Blood Knight Inugami, who's hunting down murderous cultists.
- Komiyan from Darken acquired a Morph Weapon called Blackshard, also a particularly chatty one. Before he got it he was warned to be wary of it by a Devil's consort. Currently it's possessing the body of one of his enemies, and is thrilled to have limbs. And is acting increasingly sinister. It's eventually revealed that the sword is an evil shapeshifter trapped in a gem and affixed to the sword, and was trying to drive Komi mad so it could take over his body. After fleeing it started working for Baal.
- Penny Arcade had a Genre Shift story in Japan where a man was possessed by an evil katana and forced to slaughter. When he briefly broke free of its control he drove a dagger into his eye, but it didn't let him die.
- Sluggy Freelance, of course, has Unholy Evil Death Bringer, AKA Chaz. It doesn't get more evil than "a sword powered by the blood of the innocent." Except that it is wielded by Torg, The Hero, its primary purpose is killing demons, and the sword itself claims it is only a weapon, and therefore neither good nor evil.
- It's yet another Sluggy subversion: the name, activation method and voice all indicate evil, but Chaz neither requires nor encourages evil acts, and makes no moral judgments about how its wielder uses it. Its assessment of 'innocence' is purely pragmatic, as that is the only way it can achieve maximum effectiveness as a weapon.
- Also worth pointing out that Chaz has no requirement to kill (or even injure) an innocent, only shed a sample of blood.. During a story in which the gangs souls had travelled to another dimension (long story), Zoe (under instructions from Aylee) makes a wish that causes 'innocent blood to rain in all the rooms of the house'. As soon as this is granted, Chaz gets all his powers activated.
- One of the Order of the Stick strips from its brief run in Dragon (magazine) featured a glowing black talking sword that Elan wanted Vaarsvuius to identify. When the elf told him to come back later, the sword said that it was cool, no problem, and hey, want to go kill some people while we wait?
- Keychain of Creation has Cluivnarihe, the (unpronounceable) soulsteel weapon used by Secret. To be frank, Cluivnarihe is kind of a jerk.
- The Axe of Prissan in Goblins is an inversion on this trope; it contains the soul of a powerful demon lord and emits an aura of evil. However, the axe is intended to be wielded by a good person (preferably a paladin), who must use the axe to do good deeds in order to keep the demon imprisoned.
- The Water Phoenix King has recently given us "Malice," the most powerful blade ever forged by an archangelic servant of the titular Yamra known as "The Torture Lord" to replace Our Heroine's original sword after it's broken by one of her nemeses. Genre-Savvy Anthem objects rather strenuously when discovering what her Mentor is giving her -- "You're giving me an evil sword?"—but he's confident that it won't be a problem. The blade itself, which cleaves supernatural beings with ease, looks a little bit like a straightened katana with an extra hook cut from a redshifted nebula, and was made from Kawunei's agony during the time that he and Gilgam were POWs so essentially she's carrying around a piece of his soul; he is apparently resigned to it, but not terribly happy about this.
- In The Gamers Alliance, the Sword of Darkness grants its wielder immense power but also actively corrupts him or her into becoming a dark knight. Once the sword is drawn, it can't be sheathed until it has tasted blood.
- Perhaps inevitably, the Whateley Universe has one definite, and one possible:
- The cursed longsword Imalris from Ill Winds definitely qualifies. Just summoning it devours the soul of the summoner.
- In Atop the Fourth Wall, it is averted. The soul trapped in Linkara's magic gun destroyed her parents when they tortured her to death in order to forge her into a weapon, but she considers Linkara a friend and protected him from Silent Hill's influence.
- Rubilax from Wakfu is a Sealed Demon In A Sword whose greatest desire is for absolute carnage and happens to be able to possess people.
- Scooby Doo And The Samurai Sword featured a katana called the Sword of Doom which was created by a dark forger, and thus, imbued with his evil ambitions. Upon unsheathing it, a samurai was cursed and became known as the Black Samurai. Fortunately, when Scooby Doo battled the samurai and destroyed the sword using the Sword of Fate, the Sword of Doom's opposite, the samurai was freed from his curse and his spirit was able to rest in peace.