Saffi Eriksdotter + Jackdaw Savior + Yahenni, Undying Partisan

Saffi Eriksdotter

Jackdaw Savior

Yahenni, Undying Partisan

How it works

1. Activate Saffi by sacrificing it, targeting Jackdaw Savior.
2. Activate Yahenni by sacrificing Jackdaw Savior.
3. When Jackdaw Savior dies, it and Saffi trigger.
4. Resolve the Jackdaw Savior trigger, returning Saffi from your graveyard to the battlefield.
5. Resolve the Saffi trigger, returning Jackdaw Savior from your graveyard to the battlefield.
6. Resolve the Yahenni ability.
7. Repeat.