Anti-Venom, Horrifying Healer + Agatha's Soul Cauldron + Triskelion + Conclave Mentor

Anti-Venom, Horrifying Healer

Agatha's Soul Cauldron

Triskelion

Conclave Mentor

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

This loop turns Triskelion into a self-sustaining engine by feeding it the activated abilities of Anti-Venom, Horrifying Healer through the power of Agatha's Soul Cauldron. Because Conclave Mentor increases the rate at which counters are placed, shooting Triskelion with its own ability actually results in a net gain of counters each cycle. This allows you to infinitely pump your creatures and deal unlimited damage to any target.