Red Hulk, Boromir, Warden of the Tower, and Boros Reckoner

Prerequisites

• Red Hulk on the battlefield
• Boromir, Warden of the Tower on the battlefield
• Boros Reckoner on the battlefield

Steps

1. Give Red Hulk and Boros Reckoner indestructible using Boromir
2. Deal damage to Red Hulk
3. Red Hulk triggers, putting a +1/+1 counter on it and dealing damage to Boros Reckoner
4. Boros Reckoner triggers, dealing damage to Red Hulk
5. Repeat from step 3

Results

• Infinite +1/+1 counters on a creature
• Infinite damage to one opponent