Sometimes, after a traitor makes their FaceHeel 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 HeelFace Door-Slam, where a villain regrets the wrong they've done, but it's too late for reform. Related to HeelFace 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.
- Erstin Ho from the Mai-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.
- 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.
- 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.
- 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.
- 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 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.
- Another one BioWare: The Sith Warrior recruits Malavai Quinn, a quiet and consummately professional Imperial officer. Quinn is working for Darth Baras the entire time because Baras salvaged Quinn's career. That, and a non-Force Sensitive has little rights compared to a Sith, who can rape, torture, and kill them with zero legal repercussions. Even though he's come to be more loyal to the Warrior than Baras, he still tries to get them all on the same side and hates the position he's put in.
- In Portal 2, Wheatley feels this way after you launch him into space. No longer being connected to GLaDOS's body helps.
- 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.
- 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).
- 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.
- 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 Nations. After realizing that he is descended from Avatar Roku, he has a HeelFace 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.
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!
- 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 FaceHeel 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.
- 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."