Ben 10 vs universe 7
All characters are in their prime and can only be one member.
I know this one would be against the tournament's rules but all characters that appeared in a Ben 10 episode/movie are allowed. That means the characters don't have to all be from the same universe.
No celestialsapiens because they would slap. (celestialsapien DNA still allowed)
No alternate versions
One character's power can't be in multiple members E.g:
Vilgax fused with dagon
OK so I don't know how many members are allowed to participate but here's a list of powerful characters:
Ben (UA) with the ultimatrix, master control and ascalon sword (with dagon's power) at the time
That one naljian mom (but I think we should exclude her because we don't know how powerful she is)
Verdona (again, her power is unknown)
Gwen prime/ a future version of her