Running Shingen with HP weapon is also an option then, as you could run Sniper Shot and drop Konohana for Taikoubou. Still, that setup also makes me cringe, as banking on a Soul weapon which binds you to use an R isn't particularly great. Aslo no -50% Def. Vine would cover some of that, though.

It's great that you have Belial, so you should do fine with an SR party even, but man. Fire sure could use some of their OP as fuck SSRs (Svarog, Uriel), or the support SSRs (Amaterasu, Mars). Or just overall powerhouses like Ares or the (long time from now) upcoming Awakened Acala. Alas, such is the life of Those Who Do Not Whale.