The Conspiracy of the Inner Demon

There was a battle between humans and demons, and the demon king was sealed. "I" is a pawn used by the devil to lift the seal. What an inextricable relationship I have with the Demon King. Who is the inner demon, and how does the inner demon run through thousands of years to set up a trap? What is the relationship between me and my inner demon, and what kind of past and present lives are hidden behind the conspiracy? It's all about "the conspiracy of the inner demon" This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.