Ashnod's Altar + Faceless Butcher + Metamorphosis Fanatic

Ashnod's Altar

Faceless Butcher

Metamorphosis Fanatic

How it works

1. Cast Faceless Butcher by paying its mana cost.
2. When Faceless Butcher enters, its first ability triggers, exiling Metamorphosis Fanatic.
3. Activate Ashnod's Altar by sacrificing Faceless Butcher.
4. When Faceless Butcher dies, its second ability triggers, returning Metamorphosis Fanatic from exile to the battlefield.
5. When Metamorphosis Fanatic enters, it triggers, returning Faceless Butcher from your graveyard to the battlefield.
6. When Faceless Butcher enters, its first ability triggers, exiling Metamorphosis Fanatic.
7. Repeat from step 3.

This delightfully morbid loop relies on a recursive dance between Faceless Butcher and Metamorphosis Fanatic, fueled entirely by the mana-generating sacrifice outlet of Ashnod's Altar. When Faceless Butcher enters and exiles Metamorphosis Fanatic, sacrificing the Butcher to Ashnod's Altar immediately springs the Fanatic back from exile; in turn, the returning Metamorphosis Fanatic triggers its own entry ability to pull Faceless Butcher straight back out of the graveyard. Because Faceless Butcher’s exile trigger and Metamorphosis Fanatic's resurrection trigger perpetually re-target and feed one another, you can cycle them endlessly to generate infinite colorless mana alongside an endless procession of enter-the-battlefield, leave-the-battlefield, and death triggers.