Animation Module + War Elemental + Krark-Clan Ironworks + Pandemonium

Animation Module

War Elemental

Krark-Clan Ironworks

Pandemonium

How it works

1. Cause a creature to enter the battlefield under your control.
2. Pandemonium triggers, dealing damage to an opponent equal to the creature's power.
3. War Elemental's second ability 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 the battlefield, Pandemonium triggers.
6. Holding priority, activate Krark-Clan Ironworks by sacrificing the Servo, adding CC.
7. Resolve the Pandemonium trigger, dealing 1 damage to an opponent.
8. Repeat from step 3.

This ingenious loop relies on a damage-and-counter cascade that feeds itself indefinitely. When a creature enters under your control, Pandemonium deals damage equal to its power to an opponent, which immediately triggers War Elemental to grow larger with a new +1/+1 counter. That counter creation awakens Animation Module, letting you pay a single mana to spit out a 1/1 Servo artifact creature token. That Servo's arrival triggers Pandemonium all over again, and before that damage resolves, you sacrifice the Servo to Krark-Clan Ironworks to generate the colorless mana needed to sustain Animation Module's trigger—leaving you with a rapidly scaling elemental, infinite mana, and endless damage.