Requires

Marath, Will of the Wild must be on the battlefield. Mana Echoes must be on the battlefield. Branching Evolution must be on the battlefield. Marath has at least three +1/+1 counters on it. Mana needed:

Steps

1. Activate Marath by paying and removing a +1/+1 counter from it, creating a 1/1 Elemental creture token.
2. The Elemental enters the battlefield, triggering Mana Echoes, adding for each Elemental you control.
3. Activate Marath by paying and removing a +1/+1 counter from it, putting two +1/+1 counters on it.
4. Repeat.
5. Once you have infinite , you may repeat step 3 to give Marath infinite +1/+1 counters, then use them to deal infinite damage to any target(s).

Results