Out of curiosity, is it "hard" to maximize the bubble damage that you have to roll for healing bonus circlet? Seems to me that's something you do passively building a more %atk focused Qiqi or %hp Barbara.
I can see it on Kokomi since she scales off it, but maybe on Qiqi and Barbara is overkill.
EDIT: I just tried Albedo's weapon on him, holy shit the skill damage is busted now. The sword alone gave me 500 def from the substat and it's lvl 80. The blossoms went from 7k-8k with hod to 11k, and it's rank 1.