Whatever it is, it needs to be able to credibly engage in direct head to head melee combat with two-ton fire lizards.
D&D martials are mostly not dashing from cover to cover hoping to evade detection while they set up the perfect strike. They are wading in, trusting in their toughness, equipment, and party support to keep themselves standing.
Maybe we aren't talking Thor himself (or maybe we are), but Thor's buddies should be fair game. As should your Spidermen, Caps, Black Panthers, Colossi, Juggernauts, etc.