The Red Terror + Animation Module + Phyrexian Altar + Molten Gatekeeper

The Red Terror

Animation Module

Phyrexian Altar

Molten Gatekeeper

How it works

1. Cause a creature to enter the battlefield under your control.
2. Molten Gatekeeper triggers, dealing 1 damage to each opponent.
3. The Red Terror triggers, putting a +1/+1 counter on itself.
4. Animation Module triggers, causing you to pay 1 to create a 1/1 Servo artifact creature token.
5. When the Servo enters, Molten Gatekeeper triggers.
6. Holding priority, activate Phyrexian Altar by sacrificing the Servo, adding 1.
7. Resolve the Molten Gatekeeper triggers, dealing 1 damage to each opponent.
8. Repeat from step 3.