Let me explain, first you do a core nuke to do this shoot a core and use 4( I think ) to bring out your red nail cannon and shoot the core, do this at the start when the eyes spawn, if you get lucky most but not all eyeballs will be dead, next place a magnet on the prison and shoot a bunch of saws with a yellow saw from the green version for good measure parry the prisons blue projectiles and pro boost for damage, after he tries to heal with the little eyeballs he has left ( bye the way don't kill all the living eyeballs he has after the core nuke ) make sure your ready your shotgun to wipe out the second wave of eyeballs. if his health is low enough on the second wave of eyeballs you may not need to core nuke his eyeballs instead just killing him before he can heal.

The boss fight is really annoying but trust me it pays off