Xavier Sal, Infested Captain + Agatha's Soul Cauldron + Scurry Oak + Cinderhaze Wretch

Xavier Sal, Infested Captain

Agatha's Soul Cauldron

Scurry Oak

Cinderhaze Wretch

How it works

1. Activate Xavier Sal's second ability by tapping it and sacrificing another creature, putting a +1/+1 counter on it and Scurry Oak.
2. Scurry Oak triggers, creating a creature token.
3. Activate Xavier Sal using Cinderhaze Wretch's second ability by putting a -1/-1 counter on it, untapping Xavier Sal.
4. Repeat.

This ingenious engine relies on Agatha's Soul Cauldron to grant Cinderhaze Wretch's untap ability to Xavier Sal, Infested Captain, allowing him to endlessly untap by peppering himself with -1/-1 counters. Scurry Oak acts as the perfect catalyst here, triggering to spawn a fresh Squirrel token every time Xavier Sal's proliferation grants it a new +1/+1 counter. With this loop humming along, you can infinitely sacrifice those fodder creatures to feed Xavier Sal's proliferation engine while generating an endless army of tokens and triggers.