You control at least one creature with one or more +1/+1 counters on it.
You control at least one other creature.
Thornbite Staff attached to Xavier Sal.
Xavier Sal does not have summoning sickness.
({1} magic symbol) available.
Steps
Activate Xavier Sal's second ability by tapping it and sacrificing a creature.
When the creature dies, Xavier Sal triggers, untapping Xavier Sal.
Resolve the Xavier Sal ability from step 1, putting a +1/+1 counter on a creature you control.
Animation Module triggers, causing you to pay ({1} magic symbol) to create a 1/1 Servo artifact creature token.
When the Servo enters the battlefield, Mana Echoes triggers, adding ({C} magic symbol) for each Servo you control.
Repeat.
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, and gaining infinite colorless mana due to Mana Echoes.