Aye, Sain got the idea right. Methu does not literally be exactly same (or be even completely different) from the overlord. It would be nice subtle plot if there is something what the overlord and Methu shares in common (excess, carnal pleasures, being vampire etc). Point being you have soul essence of overlord inside you (need develop story how Methu has said essence), then you get called to fortress in Hades where in fortress you get memorial recall of the earlier life the soul essence<em>had</em>before becoming Methus.<br/><br/>The memories are meant to work as glue why so diverse group of super villains (archfiends) work together instead tearing each other apart (demon vs devil nemesis nature, evil ambitions which could seek undermine the group for own personal benefit etc). Usual reason why evil campaigns do not work is because evil guys do not work together. But overlords did and they had bonds of loyalty one another, memory of said loyalty, the greatness, is meant as inspiration for archfiends to join together into council and become anew the evil overlords albeit in new form.<br/><br/>Example Kunoichi's char is connected through soul in her sword, so nothing prevents Methu be just himself but perhaps as soul eater he ate the soul of the evil overlord (from somewhere, artifact, place or other weird origin) and then since then eating he has felt calling to go to Hades. Perhaps eating said evil overlord soul unlocked some powers or promoted him to archfiend status or such.