Appa, Steadfast Guardian + Eternal Scourge + Ashnod's Altar + Chaos Shrine's Black Crystal

Appa, Steadfast Guardian

Eternal Scourge

Ashnod's Altar

Chaos Shrine's Black Crystal

How it works

1. Cast Eternal Scourge from exile by paying 3.
2. Appa's second ability triggers, creating a 1/1 Ally creature token.
3. Activate Ashnod's Altar twice by sacrificing Eternal Scourge and the Ally, adding CCCC.
4. When Eternal Scourge dies, Chaos Shrine's Black Crystal triggers, exiling Eternal Scourge from your graveyard.
5. Repeat.

This clever loop centers around Eternal Scourge, which pulls double duty thanks to its unique ability to be cast directly from exile. Once you cast it, Appa, Steadfast Guardian catches the event with its triggered ability to reward you with a 1/1 Ally token while using its flash and airbending traits to set up your board. You then feed both Eternal Scourge and the freshly minted token to Ashnod's Altar, generating a steady stream of colorless mana. As Eternal Scourge hits the graveyard, Chaos Shrine's Black Crystal steps in with its static replacement effect to instantly exile the creature instead, allowing you to seamlessly relaunch it and keep the engine humming indefinitely.