Saffi Eriksdotter + Spawning Pit + Metamorphosis Fanatic

Saffi Eriksdotter

Spawning Pit

Metamorphosis Fanatic

How it works

1. Activate Saffi by sacrificing it, targeting Metamorphosis Fanatic
2. Activate Spawning Pit by sacrificing Metamorphosis Fanatic
3. When Metamorphosis Fanatic dies, Saffi triggers, returning Metamorphosis Fanatic from your graveyard to the battlefield.
4. When Metamorphosis Fanatic enters, it triggers, returning Saffi from your graveyard to the battlefield.
5. Resolve the Spawning Pit ability.
6. Repeat.