Agatha of the Vile Cauldron + Phyrexian Altar + Ant Queen

Agatha of the Vile Cauldron

Phyrexian Altar

Ant Queen

How it works

1. Activate Ant Queen by paying , creating a 1/1 Insect creature token.
2. Activate Phyrexian Altar by sacrificing the Insect, adding .
3. Repeat.

This engine works by leveraging Agatha of the Vile Cauldron's passive cost-reduction ability to discount Ant Queen's typically demanding token-generation down to just a single green mana. Once discounted, you can repeatedly pay that single green mana to create a 1/1 Insect creature token, which is then immediately fed into Phyrexian Altar to be sacrificed for a mana of any color. Because Phyrexian Altar refunds the exact green mana needed to keep the loop going, this closed-circuit cycle generates infinite creature ETBs, leaves, deaths, and sacrifices without ever running out of fuel.