You don't. There's only Four Arms, Heatblast, XLR8, Cannonbolt and Wildvine(WHICH I bet you already know). I think they don't give us Diamondhead because his hide is pratically invincible. PLUS he can shoot diamond shards! Unless his enemy somehow manages to pin him down and find a weak point and crack his entire body into tiny weeny smitherines WHICH IS IMPOSSIBLE! Or is it?