This category is for villains who are no longer evil, which can entail joining their former heroic enemies or simply giving up on their evil cause (whatever it may be). Certain villains have died to achieve redemption, such as Darth Vader, or live on as good guys. This is usually due to villains feeling sorry for their past actions. However, villains who are already redeemed cannot be Remorseful regardless of the guilt they feel for their past crimes.

In the best cases, a redeemed villain can even go on to become Pure Good. However, this very rarely happens as most villains often retain some of their more unpleasant character traits.

There are several ways a villain can redeem themselves including:

• Snapping out of a possessed or brainwashed state, and deciding to aid the hero who freed them. The villain is a hypnotized, brainwashed or possessed pawn who does not know they are being controlled until they are freed. Grateful to whatever hero freed them, they ally with them. Count Bleck, Cyrax, and Pre-Reboot Sindel are great examples.
• Being exposed to a messiah or pure good type of hero who helps them see their errors. Usually done with delusional villains, honorable villains, insecure villains or affable villains (the villain can also have all those traits) who believe they are doing right or just want to be loved. The hero reveals to them that their actions are actually causing harm, or tries to comfort them. The individual chooses their desire for righteousness over what they have done, and/or decides the hero had helped them see what they were doing was wrong, and becomes a hero. Mitsuaki Gamou, Count Bleck, Sunset Shimmer, and Lord Business are examples.
  • Remorseful heroes: in this sub-scenario, usually in more light-hearted media, and if the villains are affable, in love and/or just plain jerks, the HEROES are the ones who apologize to the villain for provoking them into their evil ways, the villains forgive them and stop being evil. Example: Peter Rabbit and Benjamin Bunny rush back to Harrods in London to apologize to Thomas McGregor for tormenting him ever since his arrival at the McGregor manor and framing him for blowing up their burrow.
• Choosing honor before evil. A honorable villain decides that their own honor, or the honor of something or someone else, is more important than what they are doing and decide to abandon their evil actions. Often done with supporting antagonists who value the lives of lower-ranking people in an organization such as Baron Praxis and Romeo. Note: this does not count villains that betray others for selfish reasons.
• Becoming friends with someone and decide to help them over being evil, such as Axel who had planned on betraying Organization XIII with Saïx, but over time built a friendship with two other members, Roxas and Xion, and decided he was happier being with them rather than plotting with Saïx.
• Choosing their family over evil. Done with villains who have families and care for them. They realize that their actions are actually hurting their spouses, children, siblings, or any other relatives in their family. Examples are Darth Vader, Felonious Gru, Endeavor and Michael De Santa.
• Being memory-wiped or brainwashed into becoming a hero and deciding that they like their new personality and life better than their old one when they inevitably learn the truth. This is the rarest and most controversial form of a villain redeeming themselves since they did not turn good by their own free will and essentially had to be programmed into being good. The audience or reader meets them as a hero first, not knowing they are brainwashed or have fake memories. The "hero" does not know this either and is just as horrified as the viewer when they learn the truth about the horrible things they have done or regain their real memories, but they have spent so much time as a hero and living with an artificial good personality that they choose their new life over their former one and become true heroes. This also includes individuals that happened to be robotic villains that were meant/programmed to be the Big Bad's trump card against the heroes, but due to a certain incident, it ended up being discovered and fixed by the heroes that he/she meant to destroy. The said individual even later befriended the said heroes without either of them or said individual being aware of his/her true goal. One famous example is Darth Revan. Another is Professor Pericles; although he did turn good, it was only in an alternate reality and he didn't do it out of the goodness of his own heart. Pride from Fullmetal Alchemist is also a good example of this as he was memory-wiped by Edward during their confrontation, then reborn and became a normal child in the process. Raiden the Moon King from Kubo and the Two Strings is also a good example.
• Betrayed by their fellow villainous allies/bosses, which made them choose to turn to the good side. After the said villain antagonizes the hero and their deed succeeds, their allies/bosses dump them or try to kill them straightaway; either way, the said villain escapes. Having seen the error of their ways (and in the worst case, hunted down by the Big Bad or their former ally which left them with no option but to join the heroes to survive), they choose to turn to the good side by joining forces with heroes. Alain is an example. 
• Retirement of being evil: These villains chose to retire from villainy because they realized that living as a good guy is better than their previous life as evildoers. Megamind and Professor Bedlam are good examples. The former, however, did mellow out even before his retirement.
• Learning the lesson of being evil from another villain: Usually a Necessary Evil, a Monger or, in the worst of cases, a Purely Evil villain; in other words, they experience a case of "getting a taste of your own medicine", which leads them to understand that what they are doing is very bad and they feel horrified, disgusted and terribly bad for the actions of the latter villain and try to redeem himself/herself and fight against him/her (a similar but somewhat different case to Evil Vs. Evil). In the end of the battle (usually in the end of the very battle/episode/movie or in sequels), he or she will try to join the heroes and search for the pardon of everyone they had become enemies to. Shadow the Hedgehog, Lucy, and Selina are good examples.

Also, these kind of Villains are the polar opposite of Fallen Heroes.

Notes

• Pure Evil villains have no chance of any redemption, no matter the circumstances UNLESS in this case:
  • A Possessed/Brainwashed Redeemed hero can be made to look Pure Evil in a flashback or remnants of their evil actions in order to make the audience and reader initially think they are different people, which can make the twist that they are the same person more shocking to both the audience and the Possessed/Brainwashed Redeemed hero when they learn the horrific things they've done, retconning their Pure Evil status away.
  • If a Pure Evil villain does get Redeemed, they can no longer be in the Pure Evil category as those type of villains are known for being irredeemable. Even then, such cases are very rare as most formerly Pure Evil villains merely become kinder not good.
  • In addition, Pure Evil Villains who temporarily join the heroes' side out of PRAGMATIC and SELF-SERVING needs, but still retains their villainous way, can NEVER count as Remorseful, Redeemed or On & Off. It's highly possible that these kinds of villains WILL slip back into their evil ways once their needs are fulfilled. (e.g. Frieza, Slade, Sōsuke Aizen, Caesar Clown, Blood Stalk, Red Skull, Shang Tsung, etc.)
• Additionally, if the villain is currently in an On & Off status, they are NOT redeemed unless they've stayed good right up to the very end of the story. Since the part of the story where the villain appears is not complete, it is best practice to wait until it is complete to consider adding the category to the villain.
• Likewise, it is impossible for a Redeemed character to revert back to their evil ways unless they are Possessed/Brainwashed by another villain (or villains), but even so, the Redeemed villain STAYS Redeemed. That is unless they switch sides constantly.
• Villains who complete their goals, then move on without remorse, are best suited to an On & Off status, as they do nothing to make up for what they did and were merely successful in their goals, then removed or retired themselves from the action (e.g. Hatbox Ghost, Takato Keisuke, etc.)
• Redeemed villains cannot be considered Remorseful as they have been forgiven and no longer have to feel sorry for their evil actions, whereas Remorseful villains have yet to be forgiven and are still genuinely upset over their actions. However, no longer having to feel remorse does not mean they don't suffer the consquences for their behavior.
• A villain betraying another villain does not always make the villain redeemed. If a traitor is actually redeemed, they have to become heroes, apologize for their actions or stop being evil. If a villain betrays the other villain, and does not do anything else, they cannot be considered redeemed (e.g. Mr. Tweedy, Shenzi, Banzai and Ed, the Hyena Clan, Hunch, Dr. Applecheek, the Straycatchers, the Friends on the Other Side, etc.)
• A villain defeating another villain (without being a traitor) does not automatically make the villain redeemed.

See Also

• Villains' Absolution on the The Evil Wiki.
• Hero's Redemption on the Heroism Wiki.