Vigor, Walking Ballista, and Uncivil Unrest

Prerequisites

• Vigor on the battlefield
• Walking Ballista on the battlefield
• Uncivil Unrest on the battlefield
• Walking Ballista has at least two +1/+1 counters on it

Steps

1. Activate Walking Ballista's second ability by removing a +1/+1 counter from it, targeting itself, and putting two +1/+1 counters on it due to Vigor and Uncivil Unrest
2. Repeat step 1 as desired
3. Activate Walking Ballista's second ability by removing a +1/+1 counter from it, dealing 1 damage to any target
4. Repeat step 3 as desired

Results

• Infinite damage
• Infinite +1/+1 counters