Xavier Sal, Infested Captain + Haunted One + Intruder Alarm + Blasting Station

Xavier Sal, Infested Captain

Haunted One

Intruder Alarm

Blasting Station

How it works

1. Activate Xavier Sal's first ability by tapping it and removing a +1/+1 counter from the additional nontoken Human, Fungus and/or Pirate if it has one, or any counter from another permanent you control otherwise.
2. Xavier Sal triggers, causing it and all other creatures you control that share a creature type with it to get +2/+0 and gain undying until end of turn.
3. Resolve the Xavier Sal ability, causing you to populate.
4. If you created a creature token, Blasting Station triggers when the creature token enters the battlefield, untapping Blasting Station.
5. Activate Blasting Station by tapping it and sacrificing the additional Human, Fungus and/or Pirate.
6. When the creature dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
7. When the creature enters the battlefield, Intruder Alarm and Blasting Station trigger.
8. Resolve the Intruder Alarm trigger, untapping all creatures.
9. Resolve the Blasting Station trigger, untapping it.
10. Resolve the Blasting Station ability from step 5, dealing 1 damage to any target.
11. Repeat.

This looping engine turns a single sacrifice into an infinite storm of death and rebirth by letting Haunted One grant your crew the resilience of undying. Every time your creature returns to the battlefield, Intruder Alarm untaps your entire board, allowing Xavier Sal, Infested Captain to keep tapping away while Blasting Station handles the lethal payload. You simply cycle that creature through the graveyard to repeatedly trigger Blasting Station's untap ability, converting the endless stream of enters-the-battlefield events into infinite damage.