Crystalline Crawler + Evolution Witness + Cathars' Crusade + Shilgengar, Sire of Famine

Crystalline Crawler

Evolution Witness

Cathars' Crusade

Shilgengar, Sire of Famine

How it works

1. Cast the creature with mana value 1 or less from your hand by paying its mana cost.
2. When the creature enters, Cathars' Crusade triggers.
3. Holding priority, activate Shilgengar by sacrificing the creature.
4. Resolve the Cathars' Crusade trigger, putting a +1/+1 counter on each creature you control.
5. Evolution Witness triggers, returning the creature with mana value 1 or less from your graveyard to your hand.
6. Activate Crystalline Crawler by removing a +1/+1 counter from it, adding one mana of any color.
7. Repeat.

This intricate loop relies on Shilgengar, Sire of Famine to repeatedly sacrifice a tiny incoming creature for Blood tokens while feeding our graveyard, which Crystalline Crawler helps fund by cashing in its own counters for any color of mana. Whenever a creature enters, Cathars' Crusade ensures that counters spread across your board, immediately triggering Evolution Witness to pull your sacrificed creature right back from the graveyard to your hand. As you recast the creature, the entire engine loops seamlessly to generate infinite artifacts, sacrifices, and sweeping power boosts for your board.