This was a joy to read and I think I just figured out a way to improve it. Have it so that “John” is actually an acronym for J.O.H.N which can be like “Janitorial Oscillation Homing… something. Basically have him be A type of Wall-e robot that looks hyper realistically human and has been stuck alone on this outpost for hundreds of years at this point. And the reason he was successfully able to summon the Demoness is because over the long years he spent in isolation, he actually developed his own soul.