Board Thread:Ben 10 Discussion/@comment-31574541-20170324174311/@comment-28063203-20170325134030

Uh... Ultimate Way Big struggled against Diagon, one of Ben's most powerful aliens at the time.

And Thor is also physically durable to the point he's almost invulnerable to physical attacks, and has shown to have regenerated wounded body parts. He was also shown to be immune to electricity and I think even absorb it in a battle against Storm (? Is that the right hero?).

But the Mjolnir is immune to gravity. I'm not sure if Thor is, but he can fly.