Brokkos, Apex of Forever + Infested Thrinax + Pitiless Plunderer + Yahenni, Undying Partisan

Brokkos, Apex of Forever

Infested Thrinax

Pitiless Plunderer

Yahenni, Undying Partisan

How it works

1. Cast Infested Thrinax by paying 3.
2. When Infested Thrinax enters the battlefield, it triggers, causing you to create a number of 1/1 Saproling creature tokens when a nontoken creature you control dies.
3. Activate Yahenni by sacrificing Brokkos.
4. When Brokkos dies, Infested Thrinax and Pitiless Plunderer trigger.
5. Resolve the Infested Thrinax trigger, creating six 1/1 Saproling creature tokens.
6. Resolve the Pitiless Plunderer trigger, creating a Treasure token.
7. Resolve the Yahenni ability.
8. Activate Yahenni four times by sacrificing four Saprolings.
9. When the Saprolings die, Pitiless Plunderer triggers four times, creating four Treasure tokens.
10. Resolve the Yahenni abilities.
11. Activate five Treasures by tapping and sacrificing them, adding 2U/B.
12. Cast Brokkos from your graveyard for its mutate cost by paying 2U/B, putting it on top of a Saproling.
13. Repeat from step 3.

This ingenious loop relies on a clever loop of sacrifice and self-recurrence to churn out infinite resources. You use Yahenni, Undying Partisan as a free sacrifice outlet to bin Brokkos, Apex of Forever, whose own ability allows you to continually recast it from the graveyard using its mutate cost. Meanwhile, Pitiless Plunderer converts every creature death into a steady stream of Treasure tokens, providing the exact mana needed to keep the cycle going. Infested Thrinax plays a crucial supporting role by turning Brokkos into a veritable token factory, generating an army of Saprolings whenever a nontoken creature dies that can be sacrificed to Yahenni to fuel even more death triggers.