Xavier Sal, Infested Captain + Intruder Alarm + Overseer of Vault 76

Xavier Sal, Infested Captain

Intruder Alarm

Overseer of Vault 76

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 with base power 3 or less.
2. When the creature token enters the battlefield, Intruder Alarm and Overseer of Vault 76 trigger.
3. Resolve the Intruder Alarm trigger, untapping all creatures.
4. Resolve the Overseer of Vault 76 trigger, putting a counter on it.
5. Repeat.

This loop is orchestrated by Xavier Sal, Infested Captain, whose tap ability populates a creature token by removing a counter from another permanent you control, which can be done repeatedly because Intruder Alarm instantly untaps all creatures whenever that new token enters the battlefield. As the token arrives, Overseer of Vault 76 also triggers to continuously stack up quest counters, turning every iteration into a rising tide of triggers and untapped creatures. Because Xavier Sal untaps alongside your entire board, you can cycle this sequence endlessly to flood the battlefield with infinite copies of your creature tokens.