Marath, Will of the Wild + Doubling Season + Ashnod's Altar

Marath, Will of the Wild

Doubling Season

Ashnod's Altar

How it works

1. Activate Marath by paying 1 and removing a +1/+1 counter from it, creating two 1/1 Elemental creature tokens.
2. Activate Ashnod's Altar by sacrificing an Elemental, adding CC.
3. Activate Marath by paying 1 and removing a +1/+1 counter from itself, putting two +1/+1 counters on itself.
4. Repeat.
5. Once you have infinite mana, you may use it to get infinite +1/+1 counters on Marath and choose to deal infinite damage to any target(s).

This loop turns Marath, Will of the Wild into a self-sustaining engine by taking advantage of Doubling Season's replacement effects to multiply both token creation and counter placement. When you spend a counter and mana to create Elementals, Doubling Season turns that into two tokens, which you can then feed into Ashnod's Altar to generate more than enough colorless mana to keep the cycle going. Alternatively, you can use Marath's counter-adding mode—once again doubled by Doubling Season—to endlessly grow Marath, leaving you with infinite mana, infinite tokens, and infinite damage to sweep the board.