Hi !
I just finished the game. Really good, in my opinion. Well worth the few bucks that GoG charges for it. Come to think of it : even if you don't play the game and just download the soundtrack, it's still a great deal...
Well, during my playthrough, I saw the title of this thread but was afraid to open it, because of spoilers. I was somehow expecting a poor ending, but actually I was pleasantly surprised. I did not see that much references to supernatural phenomenon or even religion in this ending. From my point of view, Jade was a part of the big Domz boss that Pey'j and probably others managed to capture and trap into a human form. The bio-technology in this universe seems advanced enough to do so. Then, during the course of the game, the Domz capture people and remove their life-energy. Being a sort of special Domz, Jade manages to give the life-energy back to the population in the end. Well, I've seen endings far worse. The only disapointment I had was at the end of the credits, when Pey'j appeared to have been infected by the Domz. But, well, since they were planning on doing a sequel, I can understand. I'll just pretend I've never seen this scene :-)