Evolution Witness, Surge Conductor, Mox Opal, and Phantom Train

Prerequisites

• Evolution Witness on the battlefield
• Surge Conductor on the battlefield
• Mox Opal in hand
• Phantom Train on the battlefield

Steps

1. Cast Mox Opal by paying its mana cost
2. When Mox Opal enters, Surge Conductor triggers
3. Holding priority, activate Mox Opal by tapping it, adding one mana of any color
4. Activate Phantom Train by sacrificing Mox Opal, putting a +1/+1 counter on Phantom Train and causing it to become a creature until end of turn
5. Resolve the Surge Conductor trigger, causing you to proliferate, putting a +1/+1 counter on Evolution Witness
6. Evolution Witness triggers, returning Mox Opal from your graveyard to your hand
7. Repeat

Results

• Infinite +1/+1 counters on a creature
• Infinite artifact ETB
• Infinite artifact LTB
• Infinite artifact sacrifice triggers
• Infinite colored mana
• Infinite proliferate
• Infinite storm count