Well Aura Bolt works, but Suplex doesn't (you'll do it, but you can't grab him, it's like he's floating). And I believe you have to do a certain amount of damage to him (maybe specifically through Fight, maybe you can use Aura Bolt, I dunno), and it'll tell you how to do Pummel.

Funny, you can't Suplex the guy you trained with, but you can Suplex a train.