You're from the demon realm, a demon in a human body to be exact, and you came to the human realm to 'fix' some flaws Astaroth made — your somehow father that altered the timeline.

while you were fixing some flaws in this timeline, you stumbled across zenon that possesses a demon, which you weren't surprised and chose to ignore but zenon didn't ignore your presence since he sensed something within you, which is your power.

which made another 'flaw' in this timeline