You are trapped in the Leviathan, broken off branches of Hell that were never meant to exist. After you find the alter which will be key to your escape, you encounter a demon with green spots all over it. It is an affront to the All, and seeks to also escape the Leviathan and attack Heaven next.

Lost Unknown: At last we meet. Didn’t you know that when you broke Hell’s barrier and came here you would be broken as well? I, and I alone will storm Heaven, not you.