Animation Module + Cathars' Crusade + Phyrexian Altar

Animation Module

Cathars' Crusade

Phyrexian Altar

How it works

1. Put a +1/+1 counter on any creature you control.
2. Animation Module triggers, causing you to pay 1 to create a 1/1 Servo artifact creature token.
3. The Servo enters the battlefield, triggering Cathars' Crusade.
4. Holding priority, activate Phyrexian Altar by sacrificing the Servo, adding 1.
5. Resolve the Cathars' Crusade trigger, putting a +1/+1 on each creature you control.
6. Animation Module triggers for each +1/+1 counter placed this way.
7. Resolve all but one Animation Module trigger, choosing not to pay.
8. Resolve the final Animation Module trigger, causing you to pay 1 to create a 1/1 Servo artifact creature token.
9. Repeat from step 3.