What do you think is his real origin and how powerful do you think he really is?

IS his origion really religious or other like the previous universe theory

The wandering jew theory is a possibility but i find it hard to believe that he beat Christ. He is very mysterious and only says what needs to be said, it doesn't seem to be in his nature to hold a grudge against someone.

I'm with the theory that he's a fallen angel that didn't side with God or Satan so he's now just wandering the cosmos. Everything he's done is possible for an Angel. Angels, like Humans also have free will. Certain groups of Angels have disobeyed God and had sex with human women resulting in the giants of old. So I'm convinced that the last theory is truth.