Underworld Breach + Diligent Excavator + Thassa's Oracle + Dack's Duplicate

Underworld Breach

Diligent Excavator

Thassa's Oracle

Dack's Duplicate

How it works

1. Cast the artifact creature from your hand by paying 0.
2. Diligent Excavator and Dack's Duplicate 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 ingenious loop turns a zero-mana artifact creature—duplicated and amplified by Dack's Duplicate—into an engine of endless recursion powered by Underworld Breach. As you repeatedly cast the creature from your graveyard using escape, Diligent Excavator triggers on each historic cast to rapidly mill your entire library into the graveyard. Once your library is completely emptied, you finally cast Thassa's Oracle, whose devotion-based enter-the-battlefield trigger instantly wins you the game before you can draw from an empty library.