During the initial phase and the following phases when he shoots out a pink orb, just wait until it's close to you then jump over and move away from it to dodge it and the bolts of energy it shoots out. When it comes to the pink skulls/pigs be sure to avoid the edge of the screen portions that are 16-bit (the future) and stay within the 8-bit (past) sides; only these spots are safe from damage. when he splits into multiple forms move to about 1/4 of the room space ([not here] | [here] | [not here] | [here] | [not here]) then wait for him to line up and hit the right copy. Besides those points just time out his attack phases and then wail on him when he is in a stunned state.