Underworld Breach + Stitcher's Supplier + Infernal Plunge + Signpost Scarecrow

Underworld Breach

Stitcher's Supplier

Infernal Plunge

Signpost Scarecrow

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 Signpost Scarecrow by paying 2, adding .
5. Cast Stitcher's Supplier for its escape cost by paying and exling three other cards from your graveyard.
6. When Stitcher's Supplier enters the battlefield, it triggers, causing you to mill three cards.
7. Repeat.

At the heart of this loop is Underworld Breach, which turns your graveyard into an engine by giving every nonland card escape, letting you continually recast your threats using resources you've already spent. You sacrifice Stitcher's Supplier to fuel Infernal Plunge, and the creature's death triggers a self-mill of three cards that replenishes your graveyard just in time to pay future escape costs. Meanwhile, Signpost Scarecrow acts as a crucial color-fixing bridge, converting the red mana generated by Infernal Plunge into the black mana required to cast Stitcher's Supplier back from the graveyard. By cycling these pieces over and over, you continuously mill your entire library to set up whatever game-winning payload you desire in formats like commander, oathbreaker, and vintage.