Probably Ren Amamiya, because of his trump card Satanael and the Sinful Shell. But then again, it could be either him or Makoto Yuki and his Messiah.

I also personally feel like it’s Ren, but I feel like it’d be a pretty close match between the three.

Yeah, you got a point. Between Satanael’s Sinful Shell, Messiah’s Great Seal, and Izanagi-no-Okami’s Myriad Truths and their respective power scaling, it’s hard to determine which one is the strongest.

Yu has more charisma