Xavier Sal, Infested Captain + Animation Module + Thornbite Staff + Pitiless Plunderer

Xavier Sal, Infested Captain

Animation Module

Thornbite Staff

Pitiless Plunderer

How it works

1. Activate Xavier Sal's second ability by tapping it and sacrificing a creature.
2. When the creature dies, Xavier Sal and Pitiless Plunderer trigger.
3. Resolve the Xavier Sal trigger, untapping it.
4. Resolve the Pitiless Plunderer trigger, creating a Treasure token.
5. Activate the Treasure by tapping and sacrificing it, adding 1.
6. Resolve the Xavier Sal ability from step 1, putting a +1/+1 counter on a creature you control.
7. Animation Module triggers, causing you to pay 1 to create a 1/1 Servo artifact creature token.
8. Repeat.
9. Once you have infinite +1/+1 counters among creatures you control, you may instead use Xavier Sal's first ability to get infinite copies of creature tokens you control.

This intricate loop relies on Xavier Sal, Infested Captain wielding Thornbite Staff to weaponize and untap off its own sacrificial costs. As you sacrifice a creature to fuel Xavier Sal's proliferate ability, Pitiless Plunderer steps in to generate a Treasure token that conveniently pays the exact mana needed for Animation Module's triggered ability. Every iteration adds a +1/+1 counter that triggers the Module to churn out a Servo, providing a fresh body to sacrifice and keeping the engine perpetually running.