That was a terrible pun . But for a speculative answer to the question: Spoiler: CS4 endgame Yeah, McBurn at the height of his powers is the only member of Ouroboros who we know might be a challenge for Ein and given his and Arianrhod's status as the top fighters (and McBurn bemoaning that he's had nobody worth sparring with since Loewe's death) it's hard to imagine anyone else who's currently a member of the Society who could be anywhere near him. Cassius with his attaining of enlightenment might be somewhere in the rough vicinity and in terms of raw power Roselia is likely to be the most powerful character around (and is effectively unkillable) but it's hard to imagine any circumstance that would bring those two into a fight. So that's about it for characters we know about. I'm pretty sure before the series ends we'll see some entities that would definitely be stronger (we've still got three Sept-Terrion and an unbroken track record of them being the arc bosses) and Aidios knows what sorts of madness we'll see from the Outside. Spoiler: CS4 George aka 'Copper Georg' is literally the only one we know of. It's mentioned that many of the Gnomes (and Hexen) abandoned their mission long ago and the last time we know of them as a coherent group was almost a thousand years ago. That said, in an interview Kondo mentioned that while only Alberich and George are seen, it would be quite impossible for only two people to run the Black Workshop so there should be others that we simply didn't see. It's possible that Hajimari will at least mention their existence if not show us some of them.