Marath, Will of the Wild + Ashnod's Altar + Vorinclex, Monstrous Raider

Marath, Will of the Wild

Ashnod's Altar

Vorinclex, Monstrous Raider

How it works

1. Activate Marath by paying 1 and removing a +1/+1 counter from it, putting two +1/+1 counters on Marath.
2. Activate Marath by paying 1 and removing a +1/+1 counter from it, creating a 1/1 Elemental creature token.
3. Activate Ashnod's Altar by sacrificing the Elemental, adding CC.
4. Repeat.

This loop turns Marath, Will of the Wild into a self-sustaining engine by taking advantage of the double-counters replacement effect from Vorinclex, Monstrous Raider. Whenever you pay {1} to remove a counter and put one on Marath, Vorinclex doubles it into two, netting you a permanent +1/+1 counter growth. You can then use those counters to spawn Elemental tokens instead, which are immediately fed into Ashnod's Altar to generate the colorless mana needed to keep the cycle spinning.