User blog:ImperiexSeed/The Leviathans Destruction, how's it going to happen?

In spite of them being supposedly truly immortal, or as they put it, they can't be killed, leaving no room for defeat, however there's already something out there capable of killing them, that being Death's Scythe.

Now with that said, that means that there could very well be other things out there capable of killing them, or at least hurting them, and my question to you is, what are they?