Xavier Sal, Infested Captain + Intruder Alarm + Cloakwood Swarmkeeper

Xavier Sal, Infested Captain

Intruder Alarm

Cloakwood Swarmkeeper

How it works

1. Activate Xavier Sal by tapping it and removing a counter from a permanent you control, creating a copy of a creature token you control.
2. When the creature token enters the battlefield, Intruder Alarm and Cloakwood Swarmkeeper trigger.
3. Resolve the Intruder Alarm trigger, untapping all creatures.
4. Resolve the Cloakwood Swarmkeeper trigger, putting a counter on it.
5. Repeat.

This clever setup turns Xavier Sal, Infested Captain into an engine of endless multiplication by cycling counters into new tokens. Every time Xavier populates a creature token, Intruder Alarm springs into action to untap all creatures—including Xavier Sal—so you can tap it again right away. Meanwhile, Cloakwood Swarmkeeper feeds on each new arrival by growing larger with a +1/+1 counter, which in turn provides a fresh supply of counters for Xavier Sal to strip away and keep the loop spinning.