Junji, the Midnight Sky + Sister Hospitaller + Yahenni, Undying Partisan

Junji, the Midnight Sky

Sister Hospitaller

Yahenni, Undying Partisan

How it works

1. Activate Yahenni by sacrificing Sister Hospitaller.
2. Activate Yahenni by sacrificing Junji.
3. When Junji dies, it triggers, returning Sister Hospitaller from your graveyard to the battlefield and causing you to lose 2 life.
4. When Sister Hospitaller enters the battlefield, it triggers, returning Junji from your graveyard to the battlefield, and causing you to gain 5 life.
5. Resolve the Yahenni ability from step 2.
6. Repeat.