Ashnod's Altar + Sister Hospitaller + Wormfang Drake

Ashnod's Altar

Sister Hospitaller

Wormfang Drake

How it works

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