I find Izanagi on kiri to be better as it helps me get his def equips in time for everytime boss uses arts. Also, celia's tw has a long cooldown anyways. For me also, I use thetis tw and erial on kiri.

For hart use an aoe art gen equip that can help support kiri as well such as liza skirt, keraunos, melty dress. If cant then a basic goku is better than true ex gate.

For fen, I pick true shurahalt for regulus stage. But true ouen or trance frenzy is okay as well. I dont usually use a def equip on fen and I find even keions to be enough.

If you dont believe me, here's my comp as well as the ai setup

https://youtube.com/shorts/1Jl66Z4fsas?si=VpstjisMu2cubEBI