Sidisi, Regent of the Mire + Sister Hospitaller + Thornbite Staff + Umbral Collar Zealot

Sidisi, Regent of the Mire

Sister Hospitaller

Thornbite Staff

Umbral Collar Zealot

How it works

1. Activate Sidisi by tapping it and sacrificing a nontoken creature with mana value 5.
2. When the creature dies, Sidisi triggers, untapping Sidisi.
3. Resolve the Sidisi ability, returning Sister Hospitaller from your graveyard to the battlefield.
4. When Sister Hospitaller enters the battlefield, it triggers, returning the creature with mana value 5 from your graveyard to the battlefield and causing you to gain 5 life.
5. Activate Umbral Collar Zealot by sacrificing Sister Hospitaller.
6. When Sister Hospitaller dies, Sidisi triggers, untapping Sidisi.
7. Resolve the Umbral Collar Zealot ability.
8. Repeat.

This elegant recursive loop is centered around Sidisi, Regent of the Mire, whose tap ability trades a creature for another from your graveyard with a mana value one higher. By equipping Sidisi with Thornbite Staff, every death in the chain untaps her automatically, turning her activation into a repeatable engine. When you sacrifice a creature to Umbral Collar Zealot, you fuel the graveyard while setting up the loop. Finally, Sister Hospitaller enters the battlefield to pull your sacrificed threat right back out, generating infinite lifegain and surveil triggers along the way.