Mikaeus, the Unhallowed + Yahenni, Undying Partisan + Pith Driller

Mikaeus, the Unhallowed

Yahenni, Undying Partisan

Pith Driller

How it works

1. Activate Yahenni by sacrifiicing Pith Driller.
2. When Pith Driller dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
3. When Pith Driller enters the battlefield, it triggers, putting a -1/-1 counter on it.
4. Resolve the Yahenni ability, giving it indestructible until end of turn.
5. Repeat.

This elegant loop turns Pith Driller into a self-consuming engine, fueled by Mikaeus, the Unhallowed and his passive grant of undying to non-Human creatures. Whenever Yahenni, Undying Partisan sacrifices the Driller, Mikaeus brings it right back with a +1/+1 counter, but the Driller's own entry trigger places a -1/-1 counter on itself; state-based actions immediately cause these opposing counters to annihilate one another, leaving the creature completely clean and ready to die again. Meanwhile, Yahenni happily grows larger with every iteration while using its sacrifice ability to stay protected, generating boundless death, sacrifice, and entry triggers.