Thanks guys for the input, it's a treasure trove of good advice.
I like Mistletoe's special tbh. And yes dodge + counter is great idea, but so far only 2 rainbows (I think?) has that ability

So I've seen in many of them "last man standing" boss screenshots, it's either Kerria or Safforn as the girl, what if you put them together? Since Kerria has DEF boost, it should help...? So something like this

Safforn: Counter + Evade DEF
Nightmaher: Counter + Evade + DEF + Skill Act
Kerria: DEF + Uber special attack HP Absorb
Apricot/Habranthus: Immunity 1 turn + Counter + DEF + Skill Act
Apple Tanabata: Counter + Debuff + React + ATK

One thing is for Kerria, if I am correct she needs to activate her special to absorb HP for her to work well, maybe not enough skill act. in above team? it is 1.4x, do people spam skill flowers on Kerria?

Another thing: Would it be wise to replace one of the above with Easter Catcus uber healing ability? And she also has skill act, which is always nice. Maybe replace Apple for this idea?

Would the above work? And any improvements/suggestions?