Omarthis, Ghostfire Initiate, Helm of the Host, and Eldrazi Monument

Prerequisites

• Omarthis, Ghostfire Initiate on the battlefield
• Helm of the Host on the battlefield
• Eldrazi Monument on the battlefield
• You have a way to put a +1/+1 counter on a colorless creature you control

Steps

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

Results

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