@Otakubouzu
-He woke up and met the guy he would later fight, but Gill de Rais was in the area and sensed our undead MC enticing her to kidnap him.
-Our MC finds himself in a cave, and is forced to take a combat test and intelligence evaluation against her minions.
-After a while, Gill de Rais pretty much informs him that she works as part of that world's Illuminati hitmen.
-They turned down a prodigious contract mission to kill the "Emperor" fearing it would have too many implications or be a trap.
-Gill de Rais secretly undertakes it anyway and brings MC along for it while teaching him some new tricks.
-Gill de Rais ambushes the "Emperor" and kills many of his guards, showcasing her power.
-Upon the "Emperor" dying, he wishes fortune to the real King, as he was a mere puppet leader to the public
-The real Emperor opens a dimensional rift and proceeds to 1 shot everything, including our MC.
Edit: MC mentioned the Demon Lords started appearing after the Emperor was assassinated long ago or something to that effect. This arc is telling how it transpired, it seems every time the MC dies he keeps going further back in time.