To beat the final boss of this level (Emperor Meningitis). The battle is in 2 parts.
The first part has Meningitis attached by 3 hoses(?) to the ceiling. He has 2 attacks that always alternate, one where he shoots fire, acid or ice at you and the other in which he spits a bomb at you. Avoid his breath by flying around the room, and stop time just as he spits out the bomb, use Temporal Fist and throw the bomb into the hoses, breaking them.
The second part was very easy with a maxed out Ion Detonator. As soon as you can, stop time and toss 4 Ion bombs at his head. Unfreeze time and they will all detonate and Meningitis is beaten.