User blog comment:Twilight Despair 5/Ideas/@comment-4554525-20120416164255/@comment-3481504-20120417014129

It can in fact kill anything, dude. With that, it can kill Leviathans, however it's currently in Death's possession, making it nearly impossible to obtain.

However, it can't kill Chaos or Nature, at least according to Twilight Despair 5, as he says they can't be fully destroyed, however I confident that Death could reap them.