I RG Chickweed, she was good against the last Nushi for sure. just got her amped up last week so should be a decent fighter now too.
it really just depends what you need to fill in holes and sub in for the devs designs.
The last couple I have done
Butterfly Bush (another crit/re-act beat stick)
Chickweed (2x next turn skill act + evasion/miss)
Working on finally making a crit/counter team now, just did Firethorn working on ampies,
but it would have done terrible against last Nushi with the def reductions.
Next up is Giant Arrowhead for me then probably Rose, a waifu that fits theme.
Edit
I rearranged some teams so I could use the new event FM that gives +50 speed. It is nice to have.