Activate The Scarab God by paying {2}{U}{B}, exiling Mirror-Mad Phantasm and creating a copy of it, except it's a 4/4 black Zombie.
Activate the Mirror-Mad Phantasm token by paying {1}{U}, shuffling it into your library, revealing all cards in your library and putting them into your graveyard.
If Thassa's Oracle is not in your hand, activate The Scarab God by paying {2}{U}{B}, exiling Thassa's Oracle and creating a copy of it, except it's a 4/4 black Zombie.
If Thassa's Oracle is in your hand, cast it by paying {U}{U}.
Thassa's Oracle enters the battlefield, causing you to win the game.

Infinite self-mill

Win the game

The Scarab God

Mirror-Mad Phantasm

Thassa's Oracle

Activate The Scarab God by paying {2}{U}{B}, exiling Mirror-Mad Phantasm and creating a copy of it, except it's a 4/4 black Zombie.
Activate the Mirror-Mad Phantasm token by paying {1}{U}, shuffling it into your library, revealing all cards in your library and putting them into your graveyard.
If Labratory Maniac is not on the battlefield, activate The Scarab God by paying {2}{U}{B}, exiling Laboratory Maniac and creating a copy of it, except it's a 4/4 black Zombie.
Draw a card, causing you to win the game.

Combos with "The Scarab God"