Xavier Sal, Infested Captain + Intruder Alarm + Master Biomancer

Xavier Sal, Infested Captain

Intruder Alarm

Master Biomancer

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 two +1/+1 counters on it due to Master Biomancer.
2. When the creature token enters the battlefield, Intruder Alarm triggers, untapping all creatures.
3. Repeat.

This clever loop hinges on Master Biomancer's static ability, which ensures that any new creature token entering the battlefield arrives with a fresh stock of +1/+1 counters already on it. Xavier Sal, Infested Captain can then tap to strip one of those counters to populate, spinning out a brand-new copy of your creature token while leaving the other counter behind for future activations. Every time that fresh token hits the board, Intruder Alarm triggers its static ability to untap all creatures, including Xavier Sal, allowing you to repeat the process indefinitely for an endless army of tokens and enter-the-battlefield triggers.