Omarthis, Ghostfire Initiate + Helm of the Host + Instruments of War

Prerequisites

• You have a way to put a +1/+1 counter on a colorless creature you control.
• "Spirit" or "Naga" chosen with Instruments of War.

Steps

1. 1At the beginning of your combat phase, Helm of the Host triggers, creating a nonlegendary token copy of Omarthis with haste.
2. 2Put a +1/+1 counter on the Omarthis token or another colorless creature you control.
3. 3The nontoken Omarthis triggers, putting a +1/+1 counter on itself.
4. 4The Omarthis token triggers, putting a +1/+1 counter on itself.
5. 5Repeat from step 3.

Effects

• Infinite +1/+1 counters on a creature
• Infinite +1/+1 counters on a creature token with haste