Xavier Sal, Infested Captain + Experiment Kraj + Devoted Druid + Seeker of Skybreak

Xavier Sal, Infested Captain

Experiment Kraj

Devoted Druid

Seeker of Skybreak

How it works

1. Activate Experiment Kraj using Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
2. Activate Xavier Sal's first ability by tapping it and removing a -1/-1 counter from Experiment Kraj, creating a copy of any creature token you control.
3. Activate Experiment Kraj using Seeker of Skybreak's ability by tapping it, untapping Xavier Sal.
4. Repeat.

This clever engine comes together by loading Experiment Kraj up with the activated abilities of our other creatures, turning it into a one-stop mana and untap machine. Because Devoted Druid allows Experiment Kraj to untap itself at the cost of a counter, and Seeker of Skybreak's ability lets Experiment Kraj untap Xavier Sal, we have a perpetual motion engine for our untapped state. Xavier Sal, Infested Captain acts as the ultimate payoff here, leveraging those very same counters to populate your board endlessly while feeding back into the untap loop.