I'd like to believe that if Chara hadn't died that Toriel and Asgore would of raised them they would of grown up to be a decent human being. Not with Frisk's level of kindness or anything but still generally liked by most of the monsters. They'd still be a little weird but would forget their hatred for humanity.

Also I'd like to believe that at the end of the True Pacifist run Chara's soul is purified or at least put to rest. In the end all I think Chara needed was some love.