Cast Absorb Identity by paying {1}{U}, returning Biovisionary from the battlefield to your hand, and causing all Shapeshifters you control to become a copy of Biovisionary until end of turn.
If you control exactly three Shapeshifters, cast Biovisionary by paying {1}{G}{U}.
At the beginning of your end step, each Biovisionary triggers.
Resolve the first trigger, causing you to win the game.

Win the game

Biovisionary

Absorb Identity

Cast Absorb Identity by paying {1}{U}, returning Mirror-Mad Phantasm to your hand from the battlefield, and causing each Shapeshifter you control to become a copy of Mirror-Mad Phantasm until end of turn.
Activate a Shapeshifter by paying {1}{U}, shuffling it into your library and milling your entire library due to it not having a card named Mirror-Mad Phantasm in it.

Combos with "Absorb Identity"