Global Campaign: Encounter the Demon at the Beginning

Some people travel through time to save the world, and some people travel through time to become the strongest. I traveled so arrogantly that I actually went to work for the devil? It's not that I don't want to be loyal to humans, it's just that the other side has given me too much... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.