Bowser

Bowser is, of course, the long time nemesis of Mario. When Exor comes down to earth, it lands right on Bowser's "Keep", and forces him out. Because of this, Bowser decides that the best way to get back home is by teaming up with Mario and destroying Smithy. Bowser is all power, so he's a good choice if you want physical offense.

If you want a physical partner, pick Bowser. Although he's a bit lacking in the magic department, he's very strong. He does have a few magic attacks to keep the enemies on their toes, but attacking is his best attribute. Bowser uses chomps as a weapon, but his bare hands are excellent too, as is throwing Mario!