Fain, the Broker + Intruder Alarm + Phantom Train + Pitiless Plunderer

UB identity

Commander legal

The 4 combo pieces

• Fain, the Broker
• Intruder Alarm
• Phantom Train
• Pitiless Plunderer

What must be in place

Fain does not have summoning sickness.
You control at least one additional artifact.

How to execute it

1. Activate Fain's third ability by tapping it and sacrificing another artifact, creating a 2/1 Inkling creature token.
2. When the Inkling enters the battlefield, Intruder Alarm triggers, untapping all creatures.
3. Activate Phantom Train by sacrificing the Inkling.
4. When the Inkling dies, Pitiless Plunderer triggers, creating a Treasure token.
5. Resolve the Phantom Train ability
6. Repeat.

What the combo produces

• Infinite +1/+1 counters on a creature
• Infinite creature LTB
• Infinite death triggers
• Infinite ETB
• Infinite mana creatures you control can produce
• Infinite sacrifice triggers
• Infinite untap of creatures