Underworld Breach + Diligent Excavator + Thassa's Oracle + Mirrorhall Mimic // Ghastly Mimicry

Underworld Breach

Diligent Excavator

Thassa's Oracle

Mirrorhall Mimic // Ghastly Mimicry

How it works

1. Cast the artifact creature from your hand by paying 0.
2. Diligent Excavator and Mirrorhall Mimic // Ghastly Mimicry trigger, causing you to mill four cards.
3. The artifact creature enters the battlefield and dies as a state-based action due to having zero toughness.
4. Cast the artifact creature from your graveyard for its escape cost by paying 0 and exiling any three cards from your graveyard, except Thassa's Oracle if it is in your graveyard.
5. Repeat from step 2 until you have an empty library.
6. If Thassa's Oracle is in your hand, cast it by paying .
7. Otherwise, cast Thassa's Oracle from your graveyard for its escape cost by paying and exiling three cards from your graveyard.
8. Thassa's Oracle enters the battlefield, causing you to win the game.

This crafty loop relies on Underworld Breach to turn your graveyard into a second hand, giving your spells escape so you can recast them repeatedly. As you churn through your resources, Diligent Excavator mills your library every time you cast a historic spell like Mirrorhall Mimic // Ghastly Mimicry. Once your entire deck has hit the graveyard, you simply deploy Thassa's Oracle—either naturally or by escaping it—to instantly claim victory via its devotion-based win condition.