I've seen Water main, Mei, Sailor Sakura, and Sage Naruto being used together on a team, like so:
mei snaruto x
wm sailor sakura x
x x x
talents 32432 with the hell doggo as your summon
Naruto generates a clone every turn and sakura has her healing passive to tank damage. They're used as your tanks, the double heals from wm and sakura are your sustain, mei's chase is your control, the ignite/poison from wm and mei are your DoT, and naruto/mei are your damage. This team works best when you can outspeed your enemy, so that you get the 40% buff from mei's barrier and interrupt the enemy's r2 mystery with your sage naruto -> mei chase (takes a bit of prediction.) Hope this helps!