In many stories with fantastical or sci-fi elements, there's one particular object or weapon that the heroes rely on — perhaps a Cool Sword or Orphan's Plot Trinket that just so happens to be the source of their powers. It will always be stated as innocent or innocuous at the least, and outright holy at the most extreme. In both cases, this is the hero's trademark weapon and the crutch by which they battle and carry out their adventures; if it's of the sacred variety, the heroes may use it as a crutch for the morality of their actions, too: Sure, it might leave a bad taste in their mouths to have killed the sympathetic Anti-Villain or the Tragic Monster, but they have their holy sword! They must have the forces of Good behind them, so it's all right!
In a case like this it's not that pretty—this weapon or object works through evil means. Perhaps it's Powered by a Forsaken Child, or perhaps it's a keystone in the villain's Evil Plan, and he's manipulating the heroes into handing it over to him or powering it up for him. And of course, it could have originally been truly a holy weapon, only to be corrupted into an evil one at some point in the past.
The Reveal of this information is expected to be proportionately dramatic to the item in question's plot importance. Depending on what point in the plot the truth comes out, a variety of outcomes can occur:
- If the truth comes out early in the plot, viewers can expect a brief Heroic BSoD or 10-Minute Retirement in which the heroes attempt to cast aside the item in disgust. Sometimes they can find another power source, although usually they are persuaded to keep using it until the world is saved, when they can stop using it safely.
- The hero may attempt to purify the Unholy Holy Sword so that it really can be used safely and in the name of good. (This doesn't work with Powered by a Forsaken Child examples unless you can find a different power source — maybe one that works even better!).
- If the Unholy Holy Sword is plot-important or The Reveal occurs during the climax or penultimate stage of the story, the plot may very well shift in the direction of sealing or destroying it so that no one can use it again, if not a full-on dramatic confrontation with the villain over its true purpose.
Not to be confused with Sealed Evil in a Can, where the object contains something evil; this is innately bad. Related to the Amulet of Dependency, the Evil Weapon, and the Artifact of Doom, where an item like this is Obviously Evil. Contrast with Holy Is Not Safe, where even without being "unholy" it is still a dangerous item.
Sometimes may be an Artifact of Attraction — the very reason you wanted that sword so desperately in the first place was because it was messing with your head.
Needless to say, this is a SPOILER trope, so if you happen to be spoiler-sensitive, avert thine eyes.
- The Sword of Light in Slayers was originally thought to be a weapon of good used to defeat the Demon Beast Zanaffar, passed down in Gourry Gabriev's family. Then, in Slayers TRY, it was revealed to be part of a set of five similar weapons from another dimension, which are that reality's version of the Five Dark Lords.
- In Night Wizard, the seven Jewels of Virtue the heroes are collecting turn out to be fragments of (God of Destruction) Shaimal's power. Once the Jewels are brought together, Shaimal begins to awaken within Eris, who's horrified upon learning that she's just a vessel for Shaimal's reincarnation.
- The Evangelions from Neon Genesis Evangelion are touted as the only weapon capable of protecting the world from the Angels and The Third Impact. Turns out that A) They're cloned from angels themselves and powered by human souls — in this case, the souls of the pilots' mothers — and B) They were created to initiate Third Impact... on SEELE's terms. And not even SEELE could truly control the power they were messing with. The Third Impact that actually happens is nothing like what they wanted.
- The Red and Orange Power Rings in DC Comics (specifically the Green Lantern books). Not only are they powered by rage and greed, respectively, but their wearers become consumed with those emotions as well. Yellow Power Rings are fear-based, but their wearers generally retain their personalities.
- The Violet Power Rings are powered by love and cause their wielders to become obsessed with it, though not to the extremes of the original Star Sapphires. This is partially due to the brainwashing most recruits go through before they are taken into the Corps.
- The eponymous Amulets from Amulet. Sure, they enable to you to do neat things like lift objects, shield people, and attack, but they also expose you to an evil spirit that was responsible for a deadly civil war between the elves, and is responsible for the Elf King and Max spreading misery throughout the land due using the King's corpse as a puppet, and manipulating Max's anger over his friend's death. Also if you're not careful and rely on it too much, the Amulet will devour you.
- The Disney/Pixar movie Monsters, Inc. ventures a inversion. The monsters use the screams of small children to power... well, everything. Nobody thinks this is bad, as they're convinced children are toxic. After inadvertently scaring Boo, Sully finds a new source of energy: children's laughter, which is 10 times more powerful. Also, children aren't really toxic, just very energetic.
- In the movie Feng Shui, the lead character receives a "lucky" ba gua mirror. It is in fact lucky, in the superficial sense, but it also turns out everyone who looks in the mirror dies according to their Chinese zodiac sign.
- A more symbolic version in Star Wars. Luke receives his father's lightsaber, which helps inspire him to become a Jedi. We later find out that Anakin used it to slaughter the children of the Jedi Temple. Luke eventually loses it along with his hand in a duel with Vader, and when it turns up again three decades later, he casually tosses it aside.
- In the Inheritance Cycle, the sword Eragon gets from Brom, Zar'roc, is later found out to have belonged to the last of the Forsworn, Morzan, who was killed by Brom. This is emphasized when Eragon finds out what "Zar'roc" actually means (Misery).
- Over the course of The Hobbit and The Lord of the Rings, the One Ring is treated something like this — it's Bilbo's most prized artifact and gets him out of a lot of trouble, but once its true nature is exposed, it takes a narrative six times longer than the first book to destroy it safely.
- Gurthang, the sword of Túrin Turambar in J.R.R.Tolkien's The Silmarillion. It enables him to slay the dragon Glaurung, but it also claims the lives of many of his friends and loved ones, and in the end his own. (It's a very hungry sword and it will drink the blood of anyone, including its wielder.)
- In Memory, Sorrow and Thorn, the eponymous swords the protagonists believe they need to gather to stop the Storm King are actually the key to his return. This becomes the third version, as, after the reveal, the focus of the story abruptly shifts to how to stop the bad guys from using them. Of course, they are too late, forcing the heroes to Take a Third Option.
- In the Secret Histories novel The Man with the Golden Torc by Simon R. Green, it's revealed that the golden armor that the Drood family wears, that makes them super powered and indestructable, are powered by the souls of their dead twins which are consumed by The Heart (a giant, living crystal with godlike powers) shortly after birth.
- In The Secrets of the Immortal Nicholas Flamel, the elemental swords are well known — one is Excalibur. They also all actively consume the memories of those wounded by them, and eventually the minds of an unprotected wielder, and can potentially destroy the world if united. The heroes use one. Oops.
- The Subtle Knife from Phillip Pullman's trilogy, His Dark Materials is initially presented as a useful tool. It can cut through dimensional barriers and enables the majority of the plot to happen. However, not only are the holes it creates drawing out the Dust that powers all sentient life in the universe, but using it creates horrific monsters that eat the soul of any adults (i.e. Dust magnets) they find. Iroek is reluctant to reforge it when it breaks and Will breaks it deliberately when it is no longer needed.
- The Elric Saga: Stormbringer is a decided aversion, though it probably needs to be mentioned because it keeps popping up on this page anyway. While the sword does provide Elric with much of his strength and proves as effective when used against the forces of Chaos as against most other things, nobody even passingly familiar with the weapon is fooled in the slightest into thinking that it is not evil.
- This is retconned a bit as Moorcock's multiverse develops further. The Black Sword(s) (of which Stormbringer and its twin Mournblade are incarnations of) were actually made to fight against Chaos and any other threat to the multiverse. It's just that the Melnibonean Emperors used them to fight anything else as well. The big revelations were in finding out how important Stormbringer is to the cosmos (instead of being just a really hard-hitting magic sword) and just how evil it truly is (Elric underestimates this to great cost).
- The Stormlight Archive: This is disturbingly implied in The Way of Kings. Shardblades are the only weapons humanity possesses that can harm the demonic Voidbringers, but then you discover that Sylphrena, a being literally Made of Good, gets antsy around them and thinks Dalinar is a better man for getting rid of his. The truth is revealed in Words of Radiance. As it turns out, Shardblades are spren like Syl, who learned how to take weapon form through their bonds to the Radiants. When the Radiants broke their oaths, the bonds also broke, killing (in a manner of speaking) the spren they'd bonded to. Syl's revulsion to the shardblades is because they are the bodies of dead spren, constantly screaming in agony.
- Warbreaker features the sword Nightblood. It was created as a permanently Awakened object, infused with the command to Destroy evil. The intent was to create a weapon with the command to do only good and the will to carry it out. In practice, this backfired dramatically. What seems like a simple command to a human mind proved terribly vague to an object like a sword. Nightblood, as a sword without human experiences, doesnt have a concept of what evil is, and doesnt have the capacity to learn, though it claims its trying. Nightbloods need to consume Breath (an energy bestowed with ones soul) to function also causes it to drain the life of its wielder. What was intended to be a force for good became a weapon that controls any with ill intent who wield it, destroying everything in its path (on the off chance that there will be some evil to destroy along the way), until the user is compelled to kill himself as well. Only someone truly devoid of evil intent can even look at the sword without being controlled, and it takes a divine store of Breath to wield it safely regardless. In that way, Nightblood at least acts as a decent way to detect evil
- The Wheel of Time has Callandor, the Sword That Is Not A Sword. As a sa'angreal crystal sword that shines with light whenever the wielder channels the One Power, it has all of the trappings of a true holy sword. Except... it's flawed, lacking a buffer to prevent the wielder from using too much of the One Power, and can ensnare the wielder in a trap. Worse, though, is that it's revealed that it is also a sa'angreal for the True Power, the essence of the Dark One.
- In A Song of Ice and Fire, the legendary hero Azor Ahai reportedly forged his holy sword Lightbringer by quenching it with the life's blood of his beloved wife Nissa Nissa. In-universe the moral is supposed to be that great good can only be accomplished through great sacrifice. As characters such as Stannis attempt to re-create the legendary hero's accomplishments, the real lesson seems to be that overwhelming (and near-uncontrollable, self-destructive) power can only be attained through repeated acts of violence and ruthlessness. No end of grief has been caused by would-be Chosen Ones trying to fill Azor Ahai's shoes.
Littlefinger/Bran: Chaos is a ladder.
- And in the Game of Thrones series-adaptation, Bran the Broken becomes a Living Unholy Holy Macguffin by virtue of his extended lifespan and limited omniscience limited by his physically-crippled body and driven-to-sociopathy mind. To the lords of Westeros, he's The Prince/Princess That Was Promised: the perfect Puppet King, capable of rooting out betrayal with his clairvoyance and preventing disaster with his prediction powers for centuries to come, yet practically an object due to his crippling physical and mental disabilities, and all-too-disconnected from reality to be of any threat to them and their non-treasonous corrupt schemes. But in truth, Bran the Broken is actually a Manipulative Bastard who likely orchestrated the disgrace and deaths of their rivals along with the slaughter of their supporters and armies, and is only disconnected from their current status as king of an entire country because they're preparing to play a far greater game in the future.
- In Harry Potter, Voldemort's Horcruxes were intended to be something like this. He bound several pieces of his soul to legendary relics of the Hogwarts founders (holy, perhaps in a "civil-sacred" sense), thus seeking to blend his evil ambition with their glory. Use of this "sacred" relics causes addiction and eventually would destroy the pawn using the object.
- In Buffy the Vampire Slayer, The Slayer is humanity's guardian against evil, which includes but is not limited to vampires. Then it turns out the power of the Slayer line began when the First Slayer was imbued with the power of a demon.
- Yggdra Union has the Gran Centurio. For centuries, it was believed to be a symbol of justice incarnate. However, it was eventually revealed to be a power generator that a manipulative fallen angel planned to use as the instrument of his revenge against the gods. It so happened to run on people's hatred and pain.
- Soul Calibur of the Soul Series; a crystalline weapon of justice that is supposed to turn back the evil that is Soul Edge. However the inhabiting spirit turns out to be as bad as the sword it's designed to counter, believing that the world is unfit to continue as it is with warfare and disconcert running rampant and the only solution is eternal serenity through nothingness.
- The backstory of several Korean characters involves their trying to find the "Sword of Salvation" in order to drive out the Japanese. At first they thought it might be Soul Edge, the MacGuffin pretty much everyone else is after. After seeing its evil true nature in Soul Calibur II, they spend the rest of the series warning people of its manipulative nature, and trying to destroy it with Soul Calibur. Then Talim makes them realize Soul Calibur is just as bad.
- Mortal Kombat: Deception introduces us to Ashrah, a Netherrealm demon who fights for redemption, aided by the Kriss (a sword with a wavy blade) she wields, that guides her into slaying evil beings. However, Armageddon reveals, in what little backstory it has other than being essentially a Dream Match Game, that the Kriss is actually a Knight Templar weapon called Datusha, who just wishes to kill stuff while giving its wielder the illusion that they're slaying evil creatures for a greater good. And it's especially harmful to Vampires, thus giving Nitara (who is more on the Chaotic Neutral side of things) a motivation to join in on the fight, as Ashrah is unknowingly driving her people to extinction.
- Sudeki; the first half of the plot revolves around collecting crystals to power a "Peace Shield" around the kingdom of Haskillia, protecting it for all time. As it turns out, the crystals actually gain their power by sucking the "light" (akin to Life Force) from the mirror dimension of Akloria, leaving it to essentially rot as Haskillia blooms. To say nothing of the machine's real purpose, summoning Heigou.
- Warcraft III
- Frostmourne was originally the sword of Ner'zhul (the Lich King). He tricked Prince Arthas into using (which he did, believing it was the only way he could defeat the plague of the undead), while its true purpose was to corrupt Arthas into joining him.
- The Ashbringer zig-zags around this trope. The crystal that it was made of started as evil, but was purified. The sword itself was created as good, later corrupted, and then purified again. And then there are theories that the crystal is somehow related to Naaru, or is one, going through their dark/light reincarnations. And then in Legion, players who unlock its hidden appearance corrupt it again. It can't seem to catch a break.
- Quel'Delar, the Infinity -1 Sword of World of Warcraft: Wrath of the Lich King, goes through this stage briefly during the quest to reforge it. When it's been reforged with saronite, an ore that is actually the blood of a major Eldritch Abomination (Made of Evil, of course), it draws its owner to the vicinity of Frostmourne and attacks on its own accord. After that, it too needs to be purified.
- Chrono Trigger
- The Grandlion/Masamune is a complicated example. It's first mentioned as a heroic knight's blade, but turns out to have been filled with the power of Lavos, but is also powered by a pair of playful spirits that react to people's dreams. So it goes from good, to bad, to neutral, to good again. By Chrono Cross, it's been tainted again (by a powerful person wielding it for evil). It is purified again after the spirits' older sister Doreen shows up to chew them out for misbehaving and joins them. It then becomes the Mastermune, Serge's strongest weapon.
- Chrono Cross has the Records of Fate, which are revered in Arni as if they speak some divine and benevolent will, but it turns out they're used to control the islanders by the aptly-named supercomputer FATE.
- Brave Fencer Musashi features Lumina, the sword of luminescence, which was used to defeat the Wizard of Darkness in the distant past. Musashi claims it early in the game, and spends most of the rest of it finding and claiming the Five Scrolls that increase its power. Naturally, upon acquiring the final one, it turns out that Lumina wasn't just used to defeat the Wizard of Darkness, the Wizard of Darkness was sealed inside of it and the scrolls have been breaking the seal.
- Arcadion the Shade Sword, or The Black Sword, from Ultima VII: The Black Gate (the Forge of Virtue expansion). Forged from a supernatural metal and empowered by its captive demon, it is a superb weapon that can kill almost anything that is capable of dying, possesses many other potent powers, and the demon can offer plenty of advice on matters. On the other hand, it is a demon-powered sword and you're supposed to be the Avatar, a champion of Virtue. It's fairly far-fetched for you to want to wield the thing, or forge the cursed thing in the first place. You can avoid it by not completing the expansion, but since you start with it in Serpent Isle, Arcadion is canon.
- Heroes of Might and Magic 4
- The game has the Angel's Blade. It's not necessarily evil, and its primary function is killing undead and demons, but a quest during the campaign reveals it was created by a demon. It doesn't really matter since 1) the main character is a necromancer fighting other demons, and 2) he only needs the sword because the energy released when destroying it will open a portal to where he needs to go.
- The last campaign of Heroes Chronicles revolves around the Sword of Frost, an extremely powerful sword which is being sought by the Barbarian King Kilgor as a counter to Gelu's Armageddon's Blade, by Gelu to destroy Armageddon's Blade and keep the Sword of Frost out of Kilgor's hands, and by Tarnum to both keep it out of Kilgor's hands and keep Gelu from destroying Armageddon's Blade in the wrong way. Sadly, the wrong way that the Sword of Frost ends the terror of Armageddon's Blade is what happens... and it is by blowing up the world, leading to the events of HOMM 4.
- The Elder Scrolls IV: Oblivion's "Knights of the Nine" expansion has a variation, where there is a sword that is holy (wielded by a powerful time traveling berserker-saint who was a robotic xenophobic personification of a missing god, no less) that was cursed afterwards by someone who used it in a war for material conquest.
- The Neverland games by Idea Factory invert this with a whole slew of weapons with more or less ominous names that turn out to be potent forces of good. Among others, Demon Princess Hiro's Gate of Hell scythe can sunder someone's soul from their body and send it straight to Hell, but only works on those with an extremely evil spirit, and the Evil Spear Aleph-Beth was the weapon of choice of Arth, a holy angel who ascended to godhood and, in spite of his sudden fit of rage against humans at one point in history, was actually one of the few ascended gods who WEREN'T homicidal maniacs.
- In Hyperdimension Neptunia mk2, the main characters can come across the Gehaburn around half way through the game, leading to the infamous Conquest Ending. In order to gather power for it, Nepgear is forced to kill the CPUs and their sisters, including her own sister. Even worse, turns out this is what the Big Bad wanted all along, as with only Nepgear rulling Gameindustri, its demise is inevitable. Thankfully, in the Re;Birth2 remake, you have the option to gain a true holy sword without any sacrifices.
- Kite's Bracelet from the .hack R1 games was the heart of Cubia, the most dangerous enemy the party had ever encountered, and needed to be destroyed before said enemy could die.
- The Monado in Xenoblade is valued by the Homs for being one of the few things able to harm the dreaded Mechon, and is used by Shulk to save the lives of his friends numerous times, thanks to its abilities to let him see the future and effectively warp reality to some degree. Unfortunately, it turns out to be containing the soul of an egotistic god who intends to eradicate all life and recreate the world, and the only reason said god hadn't taken control of Shulk was because he was unknowingly following his plans for almost the entire story.
- Dark Souls features Artorias the Abysswalker, who turned his signature greatsword, which had divine properties, into a cursed blade capable of harming the ghosts residing in New Londo. His sword is tainted again in the Downloadable Content, this time by Manus, turning it into the Abyss Greatsword.
- In Phantom Brave, Sprout was once the greatest of the Four Swords of Ivoire and wielded the Sacred Sword. After his family was slain by the demon Sulphur, Sprout became obsessed with vengeance and decided to fight fire with fire by absorbing dark energy from the demons he hunts. Sprout's once Sacred Sword became an unholy blade of darkness.
- In Dawn of War III, countless people have fought and died trying to claim the legendary Spear of Khaine on the world of Acheron. The Spear is prophecised to unite the Eldar people and lead them to victory. The Eldar Autarch Kyre is especially obsessed with claiming it due to being a narcissistic Glory Seeker. The Spear turned out to be nothing but an elaborate trap. It was no weapon of an Eldar god. A powerful daemon was sealed in Acheron, and it used the Spear to lure people to it who would fight and die for it. When Kyre tried to finish off Gorgutz with the Spear, its tip shattered and unleashed dark energies that claimed Kyre himself as the final sacrifice needed to free the daemon.
- The Hero's Relics of Fire Emblem: Three Houses are said to be gifts from the Goddess Sothis. In reality? They're made from the bones of her murdered children, and the most powerful of them, the Sword Of The Creator, is made from her spine.
- The aptly-named Sword from the yuri VN Aoi Shiro. It was used to summon the divine storm that sunk the invading Mongol fleet in the past. The trope is downplayed as those with the qualifications to use it know that it's holy in the sense that "this item with terrible power is a property of the gods, do not touch," not "this is a weapon to battle evil." Also, it's not mentioned as such during the game itself, but it's the Kusanagi. It was originated from the Chaos that people in the past called Orochi, and will definitely, without exception, corrupt its user.
- Fate/stay night
- The wish-granting Holy Grail literally holds all the evil in the world, and can only grant wishes through destruction. However, this is because the summoning of an eighth Servant, Angra Mainyu (Avenger), during the Third Grail War inadvertently tainted the Grail — it wasn't like that to begin with.
- In the third route of the Visual Novel, there's also Saber's Excalibur. For the first two routes, it is a holy "Sword of Promised Victory" that fires off a beam of bright light. Halfway through the third route, she is corrupted by the evil in the Grail and becomes the newly villainous Sakura's Servant. The switch from Lawful Good to Lawful Evil is accompanied by her sword turning into the pitch-black "Excalibur Morgan" and firing off red/black beams. This is explained as being due to Morgan Le Fay's hand in its creation. It is still referred to as a holy sword, though.
- The prequel light novel and anime Fate/Zero has Arondight, Berserker's actual weapon. It used to be a holy sword that would never be damaged, made to be wielded only by a perfect knight, but when her wielder Lancelot went mad and used it to slay other Knights of the Round, it became a demonic sword filled with the madness and resentment of its master.
- The Alternate Universe novel Fate/Apocrypha has Clarent. Originally it was a sword of peace, made not for battle but for knighting and ceremonies, but was transformed into a demonic sword by Mordred's wanton hatred and used in rebellion against the lawful king, practically becoming a blood-based Excalibur. Also from same work is Balmung, which is described as being a cursed holy blade due of it possessing attributes of Gram, an actual demonic sword. It can be either a cursed sword or a holy sword depending on who wields it, with Siegfried being able to use it as a holy sword.
- Inverted in Goblins by the Axe of Prissan. It was designed to generate an aura of evilness, so that any paladins who are aware of it would seek it out in order to destroy it. Once they touch the axe, it telepathically communicates to them that it's actually being used to imprison a powerful demon who once tried to invade the Prime Material Plane, and that a paladin must constantly use it to do good deeds, which will strengthen the wards of the demon's prison and prevent it from escaping. Furthermore, it is not only incapable of harming a paladin — passing through them without leaving a wound — but it also provides its wielder with a suit of magical plate mail, to better aid the above-mentioned good deeds.
- And then it's subverted all the way to the literal Hell. The legend was a lie; the demon lord didn't reach the Material Plane nor was he defeated. The axe is a beacon forged in Hell that will allow him to travel to the Material Plane once it has stored enough energy by being used for evil acts. Paladins don't do anything to stop this as nothing works in moral absolutes, and any deed deemed good can be perceived as sufficiently evil from another point of view. For example, the axe is being wielded by a goblin who repeatedly used it against humans, which many would consider the modus operandi of the Always Chaotic Evil at a glance.
- Furthermore, the axe was forged by, and was supposed to be wielded by, Kore himself, who's one of the posterboys for Black and White Insanity thanks to the demons cursing him. Talk about a deceptive weapon....
- The 13 Months from Tower of God are a set of powerful empathic weapons given to the Princesses of Zahard. Given what we've seen from Black March, they seem rather benign and weapons of good, but slowly information is trickling through to indicate otherwise; for instance, how the Eurasia family refused to be part of the Princess system any longer after their most powerful Princess, Eurasian Enne Zahard, went berserk after she received her sword. It turns out King Zahard secretly cursed the weapons by having an Axe-Crazy woman Driven by Envy use Demonic Possession on any princess who uses more than one. King Zahard wants to forever remain on top of everyone else, but the 13 months can be used to open the doors to the floors that even King Zahard could not climb, and he cursed the swords while setting up the unfair trials to keep every climber and ranker too busy killing and backstabbing one another to disrupt the system that keeps things that way.
- The rune stones in She-Ra and the Princesses of Power, including She-Ra's Sword of Protection, give the titular princesses powers they use to fight back the Horde. The only seemingly bad part about them is that the Horde were able to get one for their own use. In truth, while the magic itself is benign and natural, the First Ones created the sword to control She-Ra for their own ends and made the runestones siphon Etheria's magic into a superweapon that would wipe out life on Etheria and a good portion of the universe if used.