Appa, Steadfast Guardian + Eternal Scourge + Ashnod's Altar + Planar Void

Appa, Steadfast Guardian

Eternal Scourge

Ashnod's Altar

Planar Void

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, Planar Void triggers, exiling Eternal Scourge from your graveyard.
5. Repeat.

This clever loop turns the self-recurring nature of Eternal Scourge into an endless engine, fueled entirely by Appa, Steadfast Guardian casting the creature from exile to generate a steady stream of 1/1 Ally tokens. With Ashnod's Altar ready to sacrifice both the Scourge and the newly minted tokens for raw colorless mana, you have more than enough power to fund the Scourge's repetitive casting costs. Meanwhile, Planar Void quietly ensures that whenever Eternal Scourge hits the graveyard, it gets whisked straight back into exile, seamlessly resetting the entire process and letting you cycle the loop infinitely for endless sacrificial benefits.