Underworld Breach + Stitcher's Supplier + Infernal Plunge + Gemstone Array

Underworld Breach

Stitcher's Supplier

Infernal Plunge

Gemstone Array

How it works

1. Cast Infernal Plunge for its escape cost by paying , exling three other cards from your graveyard, and sacrificing Stiticher's Supplier.
2. When Stitcher's Supplier dies, it triggers, causing you to mill three cards.
3. Resolve Infernal Plunge, adding .
4. Activate Gemstone Array's first ability by paying 2, putting a charge counter on it.
5. Activate Gemstone Array's second ability by removing a charge counter from it, adding .
6. Cast Stitcher's Supplier for its escape cost by paying and exling three other cards from your graveyard.
7. When Stitcher's Supplier enters the battlefield, it triggers, causing you to mill three cards.
8. Repeat.

This recursive engine relies on Underworld Breach to grant every piece in your graveyard escape, turning your discard pile into an active hand. By sacrificing Stitcher's Supplier to cast Infernal Plunge, you generate red mana while triggering the Supplier's death ability to keep your graveyard constantly refilled with fresh fodder to exile. Meanwhile, Gemstone Array acts as a crucial color-filtering engine, transforming that surplus red mana into the black mana needed to recast Stitcher's Supplier from your graveyard. Together, these cards feed into one another in an endless loop that achieves infinite self-mill to fuel whatever win condition you need.