Xavier Sal, Infested Captain + Intruder Alarm + Sigil Captain

Xavier Sal, Infested Captain

Intruder Alarm

Sigil Captain

How it works

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

This brilliant loop relies on Xavier Sal, Infested Captain to churn out token copies while continuously feeding your board state. Every time Xavier populates a 1/1 creature token, Sigil Captain swoops in with its static trigger to pump that fresh token up with two +1/+1 counters, ensuring you have plenty of fuel for Xavier's counter-removal ability. Meanwhile, Intruder Alarm acts as the engine's heartbeat, triggering off every new arrival to untap all your creatures—including Xavier Sal—so you can immediately repeat the process for infinite creature tokens and enters-the-battlefield triggers.