Ashnod's Altar + Sister Hospitaller + Fiend Hunter

Ashnod's Altar

Sister Hospitaller

Fiend Hunter

How it works

1. Cast Fiend Hunter by paying its mana cost.
2. When Fiend Hunter enters, its first ability triggers, exiling Sister Hospitaller.
3. Activate Ashnod's Altar by sacrificing Fiend Hunter.
4. When Fiend Hunter dies, its second ability triggers, returning Sister Hospitaller from exile to the battlefield.
5. When Sister Hospitaller enters, it triggers, returning Fiend Hunter from your graveyard to the battlefield.
6. When Fiend Hunter enters, its first ability triggers, exiling Sister Hospitaller.
7. Repeat from step 3.

This elegant loop relies on an infinite recursive relay between Fiend Hunter and Sister Hospitaller. When Sister Hospitaller enters the battlefield, her Medicus Ministorum ability pulls Fiend Hunter right back out of your graveyard, which immediately triggers Fiend Hunter to exile Sister Hospitaller in return. Ashnod's Altar acts as the engine that lets you cash in Fiend Hunter for a steady supply of colorless mana each cycle, all while the repetitive looping generates endless death triggers and lifegain.