Xavier Sal, Infested Captain + Saproling Burst + Intruder Alarm

Xavier Sal, Infested Captain

Saproling Burst

Intruder Alarm

How it works

1. Activate Saproling Burst by removing a fade counter from it, creating a */* Saproling creature token.
2. When the Saproling enters the battlefield, Intruder Alarm triggers, untapping all creatures.
3. Activate Xavier Sal's second ability by tapping it and sacrificing the Saproling, putting a fade counter on Saproling Burst.
4. Repeat.

This loop transforms Saproling Burst into an endless engine by carefully manipulating its fade counters. When you activate Saproling Burst to create a dynamic Saproling token, the fresh arrival immediately triggers Intruder Alarm to untap all of your creatures. This untap frees Xavier Sal, Infested Captain, allowing you to tap him and sacrifice that same Saproling to proliferate—which crucially adds a fade counter back to Saproling Burst, keeping the enchantment alive while fueling a cascade of infinite death, ETB, and untap triggers.