Underworld Breach + Malevolent Rumble + Cryptolith Rite + Lavaleaper

Underworld Breach

Malevolent Rumble

Cryptolith Rite

Lavaleaper

How it works

1. Cast Malevolent Rumble for its escape cost by paying 1 and exiling three other cards from your graveyard, causing you to mill at least three cards and create a 0/1 Eldrazi Spawn creature token.
2. Activate the Eldrazi Spawn by tapping it, adding .
3. Activate the Eldrazi Spawn by sacrificing it, adding C.
4. Repeat.

This loop lets you churn through your library by weaponizing Underworld Breach to repeatedly cast Malevolent Rumble from your graveyard. Cryptolith Rite is the linchpin that turns your freshly minted Eldrazi Spawn tokens into mana sources, while Lavaleaper ensures those tokens and any other creatures you cycle through enter with haste. By sacrificing the Spawn for colorless mana to help fund the next escape cost, you create an engine that continuously feeds its own graveyard requirements.