1. Omni Man (Invincible) - During his fight with Mark, Nolan thinks back to a baseball game from when Mark was younger, and recalls the first time he felt proud of him. Unable to bring himself to attack Mark anymore, Nolan tries one last time to try and win him over, asking him "what will you have after 500 years" to which Mark replies "I'd still have you". In this moment, Nolan realises that, somewhere along the way, the family man act he'd put on stopped being his cover story and became the real him. Ashamed, Nolan leaves the planet, later returning to fight against the Viltrum Empire. 

2. Luther (Warhammer 40k) - When Jonson was first discovered on Caliban, it was Luther who would raise him in The Order as a protégé and a son. During the Horus Heresy, Luther, having fallen to Chaos, was dispatched to Caliban to kill Jonson. Having been empowere by the 4 Chaos Gods, Luther was able to gain the upper hand and mortally wound the Primarch, but in that moment, his senses returned to him and he realised what he had done. Seeing that he was unwilling to finish the job, the Chaos Gods scattered Luther's forces around space, and Luther later allowed himself to be captured and imprisoned by the Dark Angels. 

3. Dracula (Castlevania) - Despite the protagonists' best efforts, they're still completely outmatched against Dracula. Alucard is the only one of the three who can even keep up with him, and even then it's clear that he's not going to win. As he and Dracula fight their way through the various rooms of his castle, they eventually smash through a wall that leads them into Alucard's childhood bedroom. Upon entering, Dracula halts completely in his tracks as all the memories of raising his son alongside his wife come flooding back, along with the horrifying realisation that he's about to kill the only person left in the world that he's ever loved. Overcome with melancholy, Dracula stops fighting and simply allows Alucard to kill him. 

4. Billy Butcher (The Boys) - In their final confrontation, Butcher reveals to Hughie that he intends to release the virus that will kill every supe on the planet, including Starfire and Kimiko. Unwilling to let this happen, Hughie immediately starts to fight him. For a few moments, Butcher doesn't even hit back, as he appears both shocked and genuinely impressed that Hughie is standing up to him. This soon wears off though, and Butcher quickly knocks Hughie on his ass and gets ready to send a signal to release the virus. However, as he looks down at Hughie, Butcher only sees the image of his younger brother Lenny, and we see his finger beginning to slowly release the trigger for a moment before Hughie, seeing no other choice, fatally shoots him. In his final moments, Butcher comforts Hughie, telling him he had no choice, with his last words being that Hughie is the spitting image of Lenny. 

The otherwise cold, ruthless villain gives up because they can't bring themselves to kill a loved one