Anti-Venom, Horrifying Healer + Agatha's Soul Cauldron + Triskelion + Hardened Scales

Anti-Venom, Horrifying Healer

Agatha's Soul Cauldron

Triskelion

Hardened Scales

How it works

1. Activate Anti-Venom using Triskelion'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 Hardened Scales.
2. Activate Anti-Venom using Triskelion's ability by removing a +1/+1 counter from it, dealing 1 damage to any target.
3. Repeat.