Kris is a fucking liar, it's all a scam. There is no prophecy, the roaring knight is just a demon, there is no end of the world, it's all made up and kris wields the pen. The little fucker made a deal with the devil in exchange for susie's soul but now the monkey's paw is curling and there is no way out. The devil will get his due, one way or another.

Kris chose susie because she was a bitch and he hated her but she turned out to be really nice and they've developed a genuine bond.

Ralsei is a demon developing a conscious that wants a way out but sees none.