Shepherd of the Cosmos + Yahenni, Undying Partisan + Fungal Fortitude

Shepherd of the Cosmos

Yahenni, Undying Partisan

Fungal Fortitude

How it works

1. Activate Yahenni by sacrificing Shepherd of the Cosmos.
2. When Shepherd of the Cosmos dies, Fungal Fortitude triggers, returning Shepherd of the Cosmos from your graveyard to the battlefield.
3. When Shepherd of the Cosmos enters the battlefield, it triggers, returning Fungal Fortitude from your graveyard to the battlefield attached to Shepherd of the Cosmos.
4. Resolve the Yahenni ability.
5. Repeat.

This clever loop turns Yahenni, Undying Partisan into an unstoppable, infinitely growing threat by exploiting a recursive loop between Shepherd of the Cosmos and Fungal Fortitude. Every time you sacrifice the Shepherd to Yahenni's activation, Fungal Fortitude triggers upon its death to instantly return it to the battlefield. That new entry triggers Shepherd of the Cosmos's own ability, pulling Fungal Fortitude right back out of the graveyard and reattaching it to the Shepherd so the cycle can begin anew.