Fan Casting Break the Cutie in Sort by Tropes

A series introduces a character as sweet and lovable, a fountain of Heartwarming Moments, more comic relief than anything, who likes nothing more than to pet little creatures. They make you adore them, root for them, love them and want to hug them. Then the writers proceed to slowly torment them in front of your very eyes. They destroy everything important to them, kill everyone they love and make them suffer from horrible accidents, diseases and acts of violence, including but not limited to torture, rape or any other Fate Worse than Death. They beat the character with one cruel stroke of fate after another until they are just an Empty Shell of their former cheerful, carefree self.