Mikaeus, the Unhallowed + Extruder + Grim Poppet

Mikaeus, the Unhallowed

Extruder

Grim Poppet

How it works

1. Activate Extruder by sacrificing Grim Poppet.
2. When Grim Poppet dies, its undying ability triggers, returning it from your graveyard to the battlefield without a +1/+1 counter on it due to its replacement effect.
3. Resolve the Extruder ability
4. Repeat.

This loop relies on Mikaeus, the Unhallowed to grant undying to Extruder and Grim Poppet, turning every sacrifice into an endless cycle of rebirth. When you use Extruder to sacrifice Grim Poppet, Mikaeus brings it right back to the battlefield with a +1/+1 counter. Meanwhile, Grim Poppet can leverage its own ability—or the counters it accumulates—to fuel the engine, while Extruder's sacrifice ability keeps the loop running indefinitely without ever needing to worry about echo costs.