Hofri Ghostforge + Eternal Scourge + Ashnod's Altar

Hofri Ghostforge

Eternal Scourge

Ashnod's Altar

How it works

1. Activate Ashnod's Altar by sacrificing Eternal Scourge, adding CC.
2. Eternal Scourge dies, triggering Hofri, exiling Eternal Scourge and creating a token copy of it that's a Spirit in addition to its other types.
3. Cast Eternal Scourge from exile by paying 3.
4. Activate Ashnod's Altar by sacrificing the Eternal Scourge token, adding CC.
5. The Eternal Scourge token dies, returning nothing to your graveyard due to Eternal Scourge no longer being in exile.
6. Repeat.