Carnifex Demon + Mikaeus, the Unhallowed + Phantom Train

B identity

Commander legal

The 3 combo pieces

• Carnifex Demon
• Mikaeus, the Unhallowed
• Phantom Train

How to execute it

1. Activate Phantom Train by sacrificing Carnifex Demon.
2. When Carnifex Demon dies, its undying ability triggers, returning it from your graveyard to the battlefield without a +1/+1 counter on it due to its replacement effect.
3. Resolve the Phantom Train ability
4. Repeat.

What the combo produces

• Infinite +1/+1 counters on a creature
• Infinite creature LTB
• Infinite death triggers
• Infinite ETB
• Infinite sacrifice triggers