Barrier doesn't count as a buff so Mei is a safe pick

Tendo can be used with mabui and wind blade asuma, no dmg lost if he takes no damage before he uses mystery; this will get rid of your own barrier but Roshi will break it anyway. Utakataka is a solid choice too as he can mystery after Roshi and hit many people at once (if you use poison Tai with main )

I would say something like

Wind blade asuma, x, mabui

Tend, utakata, x

X, x ,x

And

Sage naruto, Mei, x

Orochimaru konoha traitor, someone who chases Mei's mystery and makes her immobilize (low float to repulse, high float or knockdown), x.

Or you can just fill the other fields with healers/clon spammers. Achieve round 10! C=