Underworld Breach + Malevolent Rumble + Concordant Crossroads + Enduring Vitality

Underworld Breach

Malevolent Rumble

Concordant Crossroads

Enduring Vitality

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 ingenious loop turns a modest spell into an infinite engine by leveraging Underworld Breach to cast Malevolent Rumble repeatedly from your graveyard. Concordant Crossroads grants your creature tokens immediate haste, allowing the Eldrazi Spawn created by Malevolent Rumble to tap for mana right away thanks to the ability granted by Enduring Vitality. By sacrificing those same Eldrazi Spawn for colorless mana, you generate the exact resources needed to pay Malevolent Rumble's escape cost and fuel Underworld Breach's exile requirement.