Toph, the First Metalbender + Haru, Hidden Talent + Firdoch Core + Yahenni, Undying Partisan

Toph, the First Metalbender

Haru, Hidden Talent

Firdoch Core

Yahenni, Undying Partisan

How it works

1. Cast Firdoch Core by paying 3.
2. When Firdoch Core enters, Haru triggers, earthbending Firdoch Core, as it's a land due to Toph.
3. Activate Yahenni by sacrificing Firdoch Core.
4. When Firdoch Core dies, Haru triggers, returning Firdoch Core from your graveyard to the battlefield.
5. When Firdoch Core enters, Haru triggers, earthbending Firdoch Core, as it's a land due to Toph.
6. Resolve the Yahenni ability.
7. Repeat from step 3.