Mundo can do this

Pff you think that is the worst any champion has done? carves pictures into the bones of his enemies(while he makes sure that said enemies stay alive and awake during the process) flayed someone alive(someone who couldn't die,but still felt the pain),not to mention how he won't just stalk and kill you,but he will kill your friends,your family,even your pet first and then show you their tortured souls before he kills you and tortures you for eternity. enslaves your soul and forces you to kill your own allies

Graves is not a madman though.