Requires

Marath, Will of the Wild must be on the battlefield. Mana Echoes must be on the battlefield. Unbound Flourishing 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.
2. Unbound Flourishing's second ability triggers, copying Marath's ability.
3. Resolve both Marath abilities, creating two 1/1 Elemental creture tokens.
4. The Elementals enter the battlefield, triggering Mana Echoes twice, adding for each Elemental you control.
5. Activate Marath by paying and removing a +1/+1 counter from it.
6. Unbound Flourishing's second ability triggers, copying Marath's ability.
7. Resolve both Marath abilities, putting two +1/+1 counters on it.
8. Repeat.
9. Once you have infinite , you may repeat steps 5-7 to give Marath infinite +1/+1 counters, then use them to deal infinite damage to any target(s).

Results