Body Double + Metamorphosis Fanatic + Phantom Train

UB identity

Commander legal

The 3 combo pieces

• Body Double
• Metamorphosis Fanatic
• Phantom Train

How to execute it

1. Cast Metamorphosis Fanatic by paying {4}{B}{B}.
2. When Metamorphosis Fanatic enters the battlefield, it triggers, targeting Body Double.
3. Holding priority, activate Phantom Train by sacrificing Metamorphosis Fanatic, putting a +1/+1 counter on Phantom Train.
4. Resolve the Metamorphosis Fanatic ability, returning Body Double from your graveyard to the battlefield as a copy of Metamorphosis Fanatic.
5. When Body Double enters the battlefield, it triggers, targeting Metamorphosis Fanatic.
6. Holding priority, activate Phantom Train by sacrificing Body Double, putting a +1/+1 counter on Phantom Train.
7. Resolve the Body Double ability, returning Metamorphosis Fanatic from your graveyard to the battlefield.
8. Repeat from step 2.

What the combo produces

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