Think mihr is worth a mention for fire. Been running essentially a fire SR team, mainly to experiment with, and she brings some solid consistency to it.
3 turns of rampage and +20% bg fill rate (7CD), 1 turn of whole frontline taunt and intercept (idk what the multiplier is but I've seen some high numbers for the shit grid I have), then boost her combo rate (4T, 9CD).

The cds are bit high, but they haven't been a problem getting a full burst every 5 turns.

Team I use is joan (SS), nataku, mihr, brynhildr, uriel.
I have culyune and Hephaestus, but anytime I use culyunes 3rd skill it crashes the game...very annoying.