Put 2 debuffs on water Main at round 1 i.e. Immobile and ignite. Someone like Masked Man and Normal Sasuke. Only if you have Masked Man, he will also reduce Roshi and Han dmg.

Then burst her out by round 2, before she fully heals.

P.s. i dont have Masked man, so I'm still struggling to find another way to fight this team also.