Xavier Sal, Infested Captain + Intruder Alarm + Bloodspore Thrinax

Xavier Sal, Infested Captain

Intruder Alarm

Bloodspore Thrinax

How it works

1. Activate Xavier Sal's first ability by removing a counter from a permanent you control, creating a copy of a creature token you control that enters the battlefield with a +1/+1 counter on it due to Bloodspore Thrinax.
2. When the creature token enters the battlefield, Intruder Alarm triggers, untapping all creatures.
3. Repeat.

This intricate loop harnesses the engine-room synergy of Intruder Alarm to turn Xavier Sal, Infested Captain into a token-generating powerhouse. By tapping Xavier Sal to populate using a counter stripped from another permanent, you spawn a fresh token that immediately benefits from Bloodspore Thrinax's passive devour and counter-amplifying ability, ensuring it enters the battlefield with a +1/+1 counter. That new arrival triggers Intruder Alarm to untap Xavier Sal along with your entire board, resetting the captain so you can repeat the process indefinitely.