Marath, Will of the Wild + Mana Echoes + Vorinclex, Monstrous Raider

Marath, Will of the Wild

Mana Echoes

Vorinclex, Monstrous Raider

How it works

1. Activate Marath by paying 1 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 C for each Elemental you control.
3. Activate Marath by paying 1 and removing a +1/+1 counter from it, putting two +1/+1 counters on it.
4. Repeat.
5. Once you have infinite C, you may repeat step 3 to give Marath infinite +1/+1 counters, then use them to deal infinite damage to any target(s).

This loop relies on Vorinclex, Monstrous Raider's replacement effect to double every counter you generate, turning Marath, Will of the Wild's token-creation and counter-distribution abilities into a net-positive engine. When you pay mana to create an Elemental token, Mana Echoes scales exponentially with each new creature entering the battlefield to flood your pool with colorless mana. Meanwhile, you can easily shift Marath's abilities to pump itself instead, using Vorinclex to grow the commander's counter supply even faster than you spend it. Once you have built up a boundless surplus of mana, tokens, and +1/+1 counters, Marath can simply pivot its damage ability to wipe out the entire table.