I really like that guy Crit-Counter team.

My strategy for Nushi 9:
One single team on Slug path. Crit team able to beat them in 1 or 2 turns before they ultimate diamond defense.
Three teams on the other path.
1st: Crit able to kill the deadly pests in one turn (or deals enough damages to let the second one killing them without taking any damages). With as much Hit girls as possible with weakness DMG FM.
2nd: Evade team for the miss butterflies. They're the main threat here since you can kill them with a turn one Crit.
3rd: RRose and good support for her. She must kill the Nushi and she is the best one to do that.

And once the stage start, just pray pray pray and pray. It's not impossible. It just needs a perfect management and use of the four teams and they attack order.