Heliod Walking Ballista Infinite Damage

Step 1: Have both Heliod, Sun-Crowned and Walking Ballista on the battlefield.

Step 2: Ensure Walking Ballista has at least 2 +1/+1 counters.

Step 3: Activate Walking Ballista's ability to remove a +1/+1 counter and deal 1 damage to any target. Gain 1 life from the lifelink provided by Heliod.

Step 4: Heliod's ability triggers, allowing you to put a +1/+1 counter back on Walking Ballista since you gained life.

Step 5: Repeat steps 3 and 4 to deal infinite damage to any target.