It has as much health as a baron, special abilities, spams attacks, spawns enemies and has a death attack...is that really a medium level monster? Hell, this thing can survive a bfg hit. The only weakness this thing has is that the chaingun pain locks it...
So lower the pain chance to say 40 or 50, cut the health down a lot, probably lower the attack damage a touch, and please get rid of the death attacks. With all the other gimmicks on him, it is unneeded and doesn't make much sense.
I've lowered the pain chances and health and canceled out the death attacks.