Sometimes, after a traitor makes their Face–Heel Turn, they might, after some time, regret their treachery. The reasons for this may be that things didn't quite go according to plan, they realized that Being Evil Sucks, they were Forced into Evil, Trapped in Villainy, or maybe fate forced them to betray their allies. Whatever the cause, a Regretful Traitor is likely to apologize later on or in rare cases, even ask for forgiveness from their former allies. However, their former allies may not be ready to forgive them so soon.
Compare with Heel–Face Door-Slam, where a villain regrets the wrong they've done, but it's too late for reform. Related to Heel–Face Turn, where a villain (though not necessarily a traitor) joins the good side. Subtrope of Heel Realization and My God, What Have I Done?.
Due to this trope dealing with traitors, be wary of unmarked spoilers.
- Freya from Doraemon: Nobita's Drifts in the Universe betrays the Space Knight troup and sells out the earthlings to the main villain, Angolmois, resulting in Doraemon and the Knights' other earthling friends' arrest, because she genuinely believes she's doing it for the good of the Knights by ending their aimless drifts in space after being stuck in their Planet Spaceship for 300 years. She comes to deeply regret her betrayal and comes back to help the heroes escape by gunning down enemy robots in a hangar and later assists the heroes in taking doen Angolmois in the final battle.
- Erstin Ho from the My-Otome anime is one of many Schwartz spies, and in her case, she infiltrates Garderobe Academy. Even though her entire family has served Schwartz, she grows attached to her friends there in spite of her mother's warnings, and dies trying to shield Arika from Nina's attack, leaving behind a letter that calls Arika and Nina her friends.
- Homura Akemi from Puella Magi Madoka Magica The Movie: Rebellion. As if she didn't hate herself enough to begin with, her decision to split Madoka from her godlike powers, render her mortal and erase her memories of the series, while arguably necessary, was an act she considers so beyond the pale that she proclaimed herself a demon for it.
- Lazarus: When Joacquim's cybernetics are forcibly overridden by his family, he begs Forever to flee, even attempting to kill himself to stop the process.
- In The Old Guard, Sébastien "Booker" Lelivre betrays the team in hopes that this will finally enable him to die, as he's grown tired of living. He grows even more regretful upon seeing Andromache lose their Healing Factor, forcing him to confront just what said betrayal entails for all of them.
- Wonder Woman:
- Vol 1: Antiope betrays her queen Hippolyta in order to dethrone her, but regrets it before the day is through when her plan comes to fruition and ends up sacrificing herself to save Hippolyta.
- Vol 2: During The Contest Hippolyta betrays her own daughter and her people's oaths and traditions by having Diana's powers siphoned gradually to Artemis in order for Artemis to become the Wonder Woman who is prophecised to die. She is stubborn in insisting that she did what any mother would until it later becomes evident that her manipulating will lead to her daughter's death as well, by which point their relationship is already irreparably damaged.
- A Cold Calculus: Despite recognizing that the JLF have become nothing more than pawns of the SDECE, Todoh still balks at the prospect of deserting them. After they bomb Keio Hospital, he finds the resolve to follow through, but remains deeply unhappy about having to fight his former comrades.
- All For You: While All For One is willing to sell out Dr. Garaki in order to earn the privilege of being allowed to stay with his son, he isn't pleased about doing so, as they were his oldest ally, and it serves as another reminder of how he's completely dismantling his criminal empire.
- Better Luck Next Time: Haruta is forced to betray U.A. when the villains threaten to kill his sister, and deeply regrets going through with it.
- Change: While Harvest Leaf participated in attacking Princess Twilight, guilt drives them to inform Celestia and Luna where their base is.
- Never Say Never: Both Mukuro and Sakura were manipulated into betraying the other students, much to their remorse. Ironically, neither is aware of the other's status as such, which Monokuma eventually exploits for one of his motives.
- Truth and Consequences: After learning that Gabriel Agreste is Hawkmoth, Ladybug strikes a deal with him in hopes of protecting Adrien from being Convicted by Public Opinion and punished for his father's sins by ensuring the Awful Truth never comes out. Naturally, she regrets how this means that she's working against Chat Noir and the other heroes, though she tries to convince herself that the damage she's doing can be fixed once she gets her hands on his Ring.
- In Aladdin: The Return of Jafar, after Iago integrates himself with the good guys, Jafar appears before him and pressures him into helping with his plan for revenge. Iago deeply felt guilty about betraying Aladdin and the others, but had no choice because Jafar kept him under constant surveillance to ensure he did his part. The moment Jafar eased off and was no longer paying attention to him, Iago set about making things right.
- 300: Ephialtes is noticeably wincing after seeing the contempt and Stealth Insult lobbed at him by Leonidas after having sold out his fellow Greeks to the invading Persian army. He reappears in 300: Rise of an Empire as an envoy for the Persians, where he has a Please Kill Me if It Satisfies You moment with Themistocles.
- Star Wars: In The Empire Strikes Back, after the Empire arrives in Cloud City, Lando is forced to betray his old friend Han Solo by having him frozen in carbonite. Lando later makes up for it, however, by helping Leia and Chewie escape Cloud City. In the next movie he is a key character on the protagonists' side, instrumental in destroying the second Death Star.
- In Codex Alera, Fidelias betrays the First Lord to prevent what he views as inevitable civil war when he dies with no heir. When a suitable heir reveals himself, he wishes to preserve the house of Gaius. By the sixth, and last book, he has had multiple chances of just escaping while under the guise of the soldier he infiltrated the heir's forces under, but kept staying and fighting to help the heir. When he is finally found out, he is willing to accept death for his crimes until the heir's love interest convinces the heir to keep the traitor alive because they will need every capable fighter against the monstrous horde they are going to war against.
- In Dune, Dr. Yueh is truly regretful for betraying the Atreides. The Harkonnens forced him into treason by kidnapping his wife and threatening to torture or kill her if he didn't agree. They ended up killing both anyway.
- Which he expected. He knew they would never let her free, so he hoped that by doing what they said they would at least kill her rather than torture her. With the Harkonnens, the torture was likely to last *years*.
- Forgotten Realms: As of Transitions Jarlaxle has betrayed Entreri to the Netherese somewhere between books. His original plan was to betray him, then later rescue him, when he had his resources in place again. Unfortunately, he was outmaneuvered by Quenthel and Kimmuriel, who made him forget about the incident. Apparently he has regained his memories now and is deeply regretful of his actions and seeks to mend things with Entreri.
- Harry Potter:
- There's Peter Pettigrew who showed some traces of remorse even though the main reason might have been the fact that the betrayal wasn't worth what he got.
- While we don't nearly get as much about her, there's also Marietta Edgecombe, who in the wake of the work SNEAK appearing in pimples on her face after betraying Dumbledore's Army, doesn't say anything else to Umbridge to further incriminate Harry (although that's at least partly because of Shacklebolt casting a Memory Charm on her). At the very least, some fans have taken her actions after the betrayal to mean as such.
- Dragon Bones has Ward betraying the dragons again, after his ancestors did it once. His reasons are honourable, he just thinks some old dragon bones are not worth the lives of many human beings. In the end, he does the right thing, after someone explains to him just how dangerous dragon bones can be in the wrong hands. He sadly thinks about how people will remember him; a traitor of his duty (which was to protect the dragons).
- In Dragon Blood there is Garranon, who apologizes immediately after giving Ward a drugged drink of water.
- Five in Lorien Legacies.
- Officer Jeff in The Mental State acts as an informant in the police force for Saif Dhu Hadin. He even provides him with the means to control the other prisoners. However, the only reason why he does this is because Saif is paying for his daughter's medical treatments and she would die without them. He is clearly unhappy with his current predicament but unable to do anything about it. Once Zack devises a method by which Saif is forced to pay the medical bills anyway, Jeff happily accepts his punishment and even thanks Zack for what he did.
- The Sunne in Splendour: George, the Duke of Clarence, betrays his brother Edward IV because he thinks he will become king. When that doesn't work out, he deeply regrets his actions.
- In Warrior Cats, Hollyleaf murdered Ashfur to avoid him revealing to the Clans that she's the product of a forbidden relationship, and later fled the Clan and was believed to be dead. There is a novella that documents her life outside the Clan as she begins to regret her actions and forgive her birth mother, but feels that she cannot return, so she tries to help from afar by leaving them medicinal herbs and prey. Eventually she does return, after saving the lives of some ThunderClanners.
- The Zombie Knight has Melchor Blackburn (and the rest of House Blackburn), who attacked the Rainlords' rear base and captured their noncombatants, but was visibly unhappy about it even as he fought and later swore an oath to kill the man who had blackmailed them into doing so.
- Subverted with Triple H. While he might feel bad about it, especially when it comes to bite him back in the ass (see: Randy Orton), Hunter has never regretted any of his treachery. When it comes down to it, Hunter really only cares about himself and his family, and will let everyone else out to dry if he thinks it's convenient.
- Played straight with Seth Rollins. After betraying the rest of The Shield, he continuously stated that he never saw Dean Ambrose and Roman Reigns as his friends and brothers and many of his actions afterwards seemingly cemented that. However, there was more than one tell that he was actually lying, and that he truly had cared for them. After the above Triple H betrayed him, the illusion broke, and it became clear to everyone that deep down, Seth Rollins actually considered breaking up the Shield and joining the Authority to be the biggest mistake of his life.
- The Bible has the story of Judas Iscariot, who gave back his thirty pieces of silver and hanged himself after his betrayal of Jesus; alternatively, he bought a plot of land and fell down in it, spilling his guts out. Some people try to reconcile both by saying he bought a plot of land, hanged himself, and when his corpse rotted, his intestines fell out.
- Lovable Rogue Yoshimo from Baldur's Gate II turns out to be a mole planted in the party by Irenicus, and he is not happy about this in the least. Unfortunately he's under a Geas; a very powerful one at that, one that wont just kill him, but cause severe agony if he tries to disobey, so there's not a damn thing he can do about it. He's forced to betray the party once they arrive at Spellhold, and eventually meets his end when Irenicus sics him and the other servants on you to cover his escape.
- In Dreamfall: The Longest Journey Na'ane is majorly distraught over betraying the rebels at swordpoint. Made even worse by the fact that she thought she was betraying one Rebel Leader so that the rest of the rebels could survive, but ended up selling out their entire main camp.
- In Dreamfall Chapters Na'ane has become The Atoner, working her ass off to repay her debt to the rebels (who still have no idea about what she's done).
- Fake Happy End: Karin tricked the party members into helping her explore the tower so that she can find a way to escape, even though doing so means they will eventually be unable to interact with people outside the tower. She eventually comes to see them as friends and regrets lying to them.
- Final Fantasy XII has Rebel Leader and Guest-Star Party Member Vossler, who pulls a MacGuffin Delivery Service on the Player Party because he honestly believes submitting to the Empire is Dalmasca's only hope for peace and that he and Ashe are fighting a battle they cannot win. He has a Tear Jerker final scene with his old comrade Basch after the Boss Fight with him where he expresses these regrets.
- Magolor is heavily implied to be this in Kirby's Return to Dream Land. The description of his One-Winged Angel form is A sad shell possessed by the limitless power of the Master Crown, no more than a manifestation of the crown itself. He later reforms in the 20th Anniversary collection, though.
- Susie in Kirby: Planet Robobot. Her original intention upon stealing Star Dream's program controller is to sell it off for profit and teach her former boss a lesson. She winds up regretting this after Star Dream absorbs Haltmann's consciousness and condemns all organic life in the universe, leading her entrusting Kirby with the means to stop the machine and leaving her in the end with no computer, no profit, and the knowledge that she caused the death of her own father.
- Naufragar: Crimson: Hyo promises Lance that he'll revive the latter's adopted father Luhar, but only if Lance kills Athena. Lance attempts to do so by leaving Athena to die in battle against an ice dragon. The next time he's seen, he regrets his actions and decides to turn against Hyo.
- In Portal 2, Wheatley feels this way after you launch him into space. No longer being connected to GLaDOS's body helps.
- In Professor Layton and the Azran Legacy, after Emmy reveals that she's been The Mole the entire time, she expresses regret at having been so. After she's been forgiven, she resigns as Layton's assistant, feeling ashamed and unworthy to fill such a role anymore.
- Danganronpa: Trigger Happy Havoc has Sakura Ogami, the Ultimate Martial Artist. From the beginning of the Killing School Life, Sakura was The Mole for Monokuma/the Mastermind, as the fate of her family's dojo hung in the balance. Sakura was meant to get the killing started if things began to stabilise, but this never came about. Eventually, the weight becomes too much for her, and after Monokuma outs her, she poisons herself. Though as her final grace, she encourages the survivors to band together to fight back against the Mastermind and destroys a locked door before she dies. All of this proves crucial to the survivors getting out alive.
- Unsounded: Lemuel cries on the day he set up his brother for death after talking with Duane, but he does nothing to prevent the tragedy. He later cries saying he is damned for what he's done.
- In the Dream SMP, after betraying the L'Manburg revolution for kingship of the Greater Dream SMP, Eret begins to regret his actions and starts to become The Atoner, from actively wanting to help his former allies when they were exiled from L'Manburg, to overall becoming The Good King despite having no actual political power.
- In RWBY, Volume 5 features two, Leonardo Lionheart and Raven Branwen, the former once a member of Ozpin's circle as well as headmaster of Haven Academy, the latter, a former member of Ozpin's circle and a bandit tribe leader. Both only worked with Salem out of fear.
- Near the end of SMPEarth, Wisp makes up with TommyInnit after betraying his faction for the Antarctic Empire.
- Zuko from Avatar: The Last Airbender is given the choice of betraying Iroh and the peaceful life they have made for themselves so that he can come back to the Fire Nation with his honor restored. Since coming home with his father's approval is the one thing he has wanted for years, he takes the offer, leading to Iroh being imprisoned, Ba Sing Se being conquered and Aang nearly dying from Azula's lightning bolt. He spends half of the third season conflicted and confused, trying to acclimate himself to the Fire Nation despite the suffering he has seen at both his hands and the Fire Nation's. After realizing that he is descended from Avatar Roku, and seeing how ruthless his father and generals are willing to go to win the war, he has a Heel–Face Turn and leaves to join the Avatar.
- Deconstructed in Bojack Horseman. In the backstory, when BoJack's Big Brother Mentor and best friend Herb (who created the show that made BoJack a star) was outed as gay, the early 90s Moral Guardians went berserk and wanted Herb kicked off the family friendly show he had written and created. BoJack was going to threaten to quit if the network moved to fire to Herb, but the network executives talked/bribed BoJack into standing aside as Herb was fired. BoJack was quite reluctant to do this, but not so reluctant that he didn't do it, and while he had plenty of regrets, it didn't stop him from avoiding Herb for the next 20 years, until Herb was on his deathbed. Hence why, when BoJack and Herb finally talk about it all those years later, Herb rejects BoJack's attempt to apologize. Pointing out what else he could have done and why he ended up not doing it.
BoJack: You have to believe me. I did everything I could.
Herb: Yeah? Then why didn't you call me? Huh? Twenty years, you didn't call me. Do you know what it was like for me? I had nobody. Everybody left! I knew all those showbiz phonies would turn on me, sure. But you?
BoJack: It's not my fault you got fired.
Herb: I don't care about the job! I did fine, I had a good life, but what I needed then was a friend. And you abandoned me. And I will never forgive you for that. Now get the fuck out of my house!
Herb: Know what your problem is? You want to think of yourself as the good guy. Well, I know you better than anyone, and I can tell you that you're not. In fact, you'd probably sleep a lot better at night if you just admitted to yourself that you're a selfish goddamn coward who just takes whatever he wants and doesn't give a shit about who he hurts. That's you. That's BoJack Horseman.
BoJack: I don't know why I came here.
Herb: Yeah... You do.
- Elena of Avalor: 41 years prior to the series, Princess Elena's cousin Esteban secretly made a deal with the evil sorceress Shuriki to help take over the kingdom, and she promised no one would be hurt. However, she ended up killing the King and Queen, leading Esteban to regret his decision ever since. Eventually, he turned on Shuriki and helped Elena take the kingdom back, but he still refused to tell her of his involvement, but he's felt guilty for the choice he made back then. Unfortunately, Elena found out about his treachery from all those years ago, and is understandably enraged and hurt at this revelation. Esteban tries to explain that he's changed since then, but Elena disowns him, and Esteban ends up betraying her again, believing that she hates him.
- Final Space: Season 3 reveals Avocato deeply regretted betraying and assassinating the king and queen of his homeworld on the Lord Commander's orders in his backstory. He's still deeply ashamed of the act in the present and hates himself. Especially since the king and queen were Little Cato's biological parents.
- Sunset Shimmer apologizes at the end of My Little Pony: Equestria Girls and asks the Mane 6 for their forgiveness. Furthermore, the entire sequel My Little Pony: Equestria Girls – Rainbow Rocks deals with her seeking forgiveness from the rest of Canterlot High. Although her original Face–Heel Turn is not shown on screen, she is nonetheless a traitor from Celestia's point of view, and sees herself as one in Rainbow Rocks too. My Little Pony: Equestria Girls – Forgotten Friendship has Sunset finally reconciling with Princess Celestia and being forgiven.
- She-Ra and the Princesses of Power: The fourth season has this as part of Catra's season-long Villainous Breakdown, with her being plagued with bad dreams about what she did to Entrapta the previous season.
- The Simpsons: In "24 Minutes" (a parody of 24), Martin Prince gives himself a wedgie — which is portrayed as if he was hanging himself — after he's forced to be The Mole.
- Teen Titans: When Terra sets up Titan Tower to be attacked, she gets enough cold feet to try to save Beast Boy and eventually breaks down apologizing to him when he finds out. Beast Boy doesn't accept it and says they were never friends. After that, she explicitly says she has no regrets and tries her best to kill the Titans herself, but it's made obvious that's she still more conflicted than that.
- Benedict Arnold's last words were supposedly, "Let me die in this old uniform in which I fought my battles. May God forgive me for ever having put on another."