Anti-Venom, Horrifying Healer + Agatha's Soul Cauldron + Walking Ballista + The Earth Crystal

Anti-Venom, Horrifying Healer

Agatha's Soul Cauldron

Walking Ballista

The Earth Crystal

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 The Earth Crystal.
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.

This potent loop revolves around Agatha's Soul Cauldron exiling Walking Ballista so that your creatures can harness its activated abilities. Anti-Venom, Horrifying Healer gets those crucial +1/+1 counters to start granting abilities and can even help recur your pieces from the graveyard when cast. Meanwhile, The Earth Crystal doubles every counter placed on your creatures, turning Walking Ballista's self-inflicted damage into a net gain of counters. By pinging the board and repeatedly growing your creatures, you can continuously convert those counters into infinite damage.