Anti-Venom, Horrifying Healer + Agatha's Soul Cauldron + Angrath's Marauders + Walking Ballista

Anti-Venom, Horrifying Healer

Agatha's Soul Cauldron

Angrath's Marauders

Walking Ballista

How it works

1. Activate Anti-Venom using Walking Ballista's ability by removing a +1/+1 counter from it, targeting itself and putting two +1/+1 counters on it due to its replacement effect and Angrath's Marauders.
2. Activate Anti-Venom using Walking Ballista's ability by removing a +1/+1 counter from it, dealing 1 damage to any target.
3. Repeat.

By exiling Walking Ballista into Agatha's Soul Cauldron, any creature you control with a +1/+1 counter gains the ability to ping for damage. If that creature is Anti-Venom, Horrifying Healer, the damage it tries to deal to itself is prevented and converted into +1/+1 counters instead. Thanks to the damage-doubling presence of Angrath's Marauders, self-inflicted damage generates a net positive surge of counters. This creates a self-sustaining loop where Anti-Venom grows infinitely large and can redirect its excess firepower to deal infinite damage to any target.