On second thought, if you do move Acala to the bench for Konohana Sakuya, instead move Acala to the 2nd bench slot. If you don't start losing girls until Kyuuki is back in normal, then Acala doesn't do much right away. Brynhildr's heal and +double atk would probably be more useful as your formation shouldn't be completely broken yet. And if you beat Kyuuki before she goes into raging again, then consider completely replacing Acala with some other R or SR with direct damage skills to pump out instant damage.

I think of placing Acala in the first bench slot as I've been used to losing someone during raging, but Joan's damage cut (and/or Da Ji's wind resist buff here) significantly reduces the odds of that happening against Kyuuki. I need to adjust to that myself, actually. I was using Cassiopeia during Kyuuki's first run, but since then I've gained Hephaestus/Brynhildr, thus enabling me to switch to Joan.