To go into detail about Agamo, his special attack it to rip his head off and use it as a weapon. Most levels are typically littered with weapons a minute into a fight, so why use him? As mentioned earlier weapons restore energy, so odds are you'll always have a better weapon than what's lying around. In addition, this weapon can be made to explode on command, either when your opponent is dumb enough to pick it up after a throw or (with a bit of timing,) after it bounces off of them from a throw.
I'm just gonna leave this here.