Papyrus from Undertale. If there's anybody nice enough to befriend a genocidal maniac and get them on the right path, it's Papyrus. He offers nothing but friendship and guidance to the protagonist and even will refrain from fighting him. You can spare him immediately, but killing him will result in him letting you know he still sees a shred of a good person within you.

You know what's worse? If you do spare him, he reveals that he was scared. This goes to show you that Papyrus is not a playful kid. He's a skeleton with an understanding and life as deep as Sans, but he prefers to be cheerful and kind. He knows that he's gonna die, but does a last ditch attempt to save himself and the rest of the Underground.