AlienWarlord
He's probably totally naked due to the ritual .... Or his eyes became snake eyes ... Or he got taller and his physique became better ... Or his skin became so white , and has little scales like a snake (imagine kabuto but with a lesser changer) Or his hair became snakes (i don't think this happened , though)
It's not about the MC having the op's subordinates or not, but where is the logic? if indeed being the master of the Death Existence was as easy as we saw from Tok Riddle getting those 3 items, then Thanos would not go around the world to destroy half of the universe just to get Lady Death's attention.