Cast Selective Memory by paying {3}{U}, exiling all nonland cards in your library.
Cast Demonlord Belzenlok by paying {4}{B}{B}.
When Demonlord Belzenlok enters the battlefield, it triggers, exiling the remainder of your library.
Cast Thassa's Oracle by paying {U}{U}.
When Thassa's Oracle enters the battlefield, it triggers, causing you to win the game.

Win the game

Exile your library

Demonlord Belzenlok

Selective Memory

Thassa's Oracle

Cast Selective Memory by paying {3}{U}, exiling all nonland cards in your library.
Cast Demonlord Belzenlok by paying {4}{B}{B}.
When Demonlord Belzenlok enters the battlefield, it triggers, exiling the remainder of your library.
The next time you would draw a card, you win the game due to Laboratory Maniac.

Laboratory Maniac

Cast Selective Memory by paying {3}{U}, exiling all nonland cards in your library.
Cast Demonlord Belzenlok by paying {4}{B}{B}.
When Demonlord Belzenlok enters the battlefield, it triggers, exiling the remainder of your library.
Activate Jace's first loyalty ability by putting a loyalty counter on it, causing you to mill two cards and win the game due to drawing from an empty library.

Combos with "Demonlord Belzenlok"