Hard to say what's best without knowing what you already got. There are so many good ones.
You need a 30%? Weakness? 1.65 skill act?
My favorite for the team crit is Onci Valentine fits anywhere with remaining enemies skill, good speed 635, with re-action, basic skill act, and 20% rate/45% dmg
https://flowerknight.fandom.com/wiki...id_(Valentine)
Look through some of these. Filter for crit dmg.
https://flowerknight.fandom.com/wiki/List_of_Abilities