Redeeming Replacement

A rarer occurrence which is in some ways the inverse of Anti-Hero Substitute, this is a Comic Book trope wherein one holder of a certain identity (usually a Legacy Character) is a hero despite all other versions of that character being villains. Sometimes the character taking on this persona will speak of a desire to "redeem" that identity, especially if they are a child of the villainous wearer of the costume. Arguably, this trope happens for similar reasons as the Anti-Hero Substitute. The Anti-Hero Substitute aims to makes a hero "cooler" by having a character with the hero's powers but less restraint in using them. In a similar way, Evil Is Cool, and this trope allows villain powers to be showcased, but by a character with heroic aims.

Anime & Manga

 * In a way, Dark Schneider in Bastard!! is one of these. The original Dark Schneider was pretty much an Evil Overlord, but then was sealed in a young boy. Thanks to the goodness of the "container", while the new Dark Schneider has the personality of the original (a lecherous egomaniac), he is a saint compared to the original.
 * This is largely Sai Akuto's goal in Ichiban Ushiro no Dai Maou. Of course, it's rather hard to win the trust of the people when the Sorting Hat vocational raven says that you're going to be a Demon King.

Marvel Universe

 * In the Spider-Man universe, Phil Urich stumbled on a Green Goblin costume and got doused in the Super Serum (note, it was explicitly this -- unlike the earlier Psycho Serum, this one didn't make you insane), producing the irony of a guy a lot like Peter Parker (snarky journalist Unlucky Everydude) taking on the identity of Peter's worst enemy. In the main Spider-Man series, Urich did end up suffering from mental problems and ultimately pulled a Face Heel Turn.
 * In the Spider-Girl series, things went better, and he is an Honorary Uncle to the heroine, and has moonlighted as a superhero in both his Green Goblin costume and as the "Golden Goblin" (basically a Palette Swap Hobgoblin).
 * Also in the Spider Girl series is Normie Osborn. Following his father and grandfather, he took on the Green Goblin identity as a villain, but after conquering his demons ended up being a Redeeming Replacement for Venom (although he doesn't call himself that)- he was forcibly merged with the symbiote but managed to stay mostly sane with it and fight crime. Similarly to the irony with Urich, Normie is a friend and love interest to May Parker, despite running around in the costume of one of her father' worst enemies.
 * And, the series has another example in Brenda Drago, Raptor, who ends up marrying Normie Osborn. She's the daughter of Blackie Drago, the second Vulture and started out as a criminal, but then reformed and became an antihero.
 * The version of Sabretooth that was a member of the Exiles was a hero from an Alternate Reality. The "real" Sabretooth is a Complete Monster.
 * While on his deathbed, B-List supervillain the Black Knight begged his nephew Dane Whitman to restore honor to their family legacy and to atone for his crimes. Whitman did so, becoming a heroic Black Knight still active to this day. The villainous Black Knight is also something of an inversion: he based the identity and his equipment off of his heroic ancestor, the medieval Black Knight.

DC Universe

 * One version of Toyman is a young Japanese genius, while the other versions of the character are all villains.
 * Unfortunately he, like all other versions, turned out to be a super-advanced android, created by the one and only original Toyman.
 * The Red Hood, which is generally told as being an identity of The Joker before he became a Monster Clown. The identity is also used by some of the Robins, mainly Jason Todd, typically when acting as anti-heroes.
 * And in Batman the Brave And The Bold, it was the identity of a good Joker from an Alternate Universe.
 * The female Dr. Light, who (like the Toyman example above) is a Japanese genius. She's also a Hot Scientist and Mama Bear - as opposed to the first Dr. Light, who was a man, a villain, and a rapist (by retcon).
 * This is the basic idea behind Brainiac 5 of the Legion of Super-Heroes, descendant of Brainiac the Superman villain. (There are intervening Brainiacs of varied morality, but they weren't really focused on until well after B5 had been introduced.)
 * Also from the Legion, Danielle Foccart assumed the codename "Computo" in the V4 era when she gained Technopathic powers -- after the villainous AI that possessed her in her first appearance (her brother Jacques' origin as the second Invisible Kid).
 * Faust, a (generally) heroic magic-user in the DCU is the son of Justice League of America villain Felix Faust.
 * The Golden Age villain Brain Wave had a son that called himself Brain Wave Jr. and became a member of Infinity Inc. Of course, he's now gone a long way from being the hero that he was.
 * Owen Mercer, the son of the first Captain Boomerang, tried to be one of these.
 * One story in the Kingdom Come universe had Iris "Kid Flash" West encounter the Fiddler's great-grandson, Iowa Bowin, who believed his ancestor had "a headful of bad wiring", and wants to use his guitar version of Isaac's weaponised violin to be a hero.

Other

 * In Astro City, the heroine Quarrel is the daughter of a super-villain who was also named Quarrel.
 * There's an example of this in Watchmen where at the end of novel, Laurie discusses a change of costume design into one that looks like that of the Comedian, . While the Comedian was technically a hero, being the Token Evil Teammate of the original team of heroes, this example probably still fits.

Tabletop Games

 * Hunter: The Vigil: The life tenet of the Lucifuge is basically "we are Satan's children, but we protect humanity from the darkness". They are also the nicest Hunters when it comes to dealing with the more decent supernaturals. The other children of Satan, however...
 * To lesser extent, the Loyalist of Thule.
 * Exalted: Some of the modern Solars try to be this. Even the Abyssals and Infernals can at least try.

Film

 * In The League of Extraordinary Gentlemen film, the Invisible Man is one Rodney Skinner, a Lovable Rogue cockney thief who apparently stole the formula from Griffin of the novel, a psychopathic Invisible Jerkass.
 * Dave is about the United States President being replaced by one of these.

Live Action Tv

 * Thanks to The Nth Doctor and the Timey-Wimey Ball, The Doctor of Doctor Who sometimes functions as one of these to himself.

Video Games

 * Mass Effect 2 has, a . While Commander Shepard has blasted through enough of these things to melt them down and rebuild the Normandy,
 * In Mortal Kombat, in both the games and the Lighter and Softer (but still accurate to continuity) animated series, the original Sub Zero was a villain/AntiVillain, and is succeeded by his younger brother, who fights on the side of the heroes.
 * In Adventure Quest Worlds The Hero can act as a Redeeming Replacement to any villain and with Doom Knight Overlord Class the hero can act as one to Sepulchure

Web Original

 * In the Global Guardians PBEM Universe, the current Stuntman (a hero) is the only son of the original Stuntman (a villain). The father of Dream Catcher, a psychic hero with the power to turn dreams into reality, was active as a villain in the late 1970s/early 1980s and used the same name and the same powers (he's now in a mental institution).