Strength of Will + Hardened Scales + Walking Ballista

Strength of Will

Hardened Scales

Walking Ballista

How it works

1. Cast Strength of Will by paying 1, targeting Walking Ballista.
2. Activate Walking Ballista by removing a +1/+1 counter from it, dealing 1 damage to it.
3. Walking Ballista triggers, putting two +1/+1 counters on it due to Hardened Scales.
4. Activate Walking Ballista by removing a +1/+1 counter from it, dealing 1 damage to any target.
5. Repeat from step 2.

This loop transforms Walking Ballista into a self-sustaining engine by turning its own damage into growth. With Strength of Will granting the construct indestructible and a triggered ability whenever it takes damage, shooting the Ballista triggers its own growth while Hardened Scales steps in to add an extra counter every time. Because the damage dealt by the Ballista's first ability triggers two counters to be placed on it, you net a positive counter each cycle—allowing you to pump it infinitely large and unleash infinite damage to any target.