Dualcaster Mage, Unearth, and Phantom Train

Prerequisites

• Dualcaster Mage in hand
• Unearth in hand
• Phantom Train on the battlefield
• available

Steps

1. Cast Unearth by paying , targeting any applicable target
2. Holding priority, cast Dualcaster Mage by paying
3. When Dualcaster Mage enters, it triggers, targeting Unearth
4. Holding priority, activate Phantom Train by sacrificing Dualcaster Mage
5. Resolve the Dualcaster Mage trigger, copying Unearth, with the copy targeting Dualcaster Mage
6. Resolve the Unearth copy, returning Dualcaster Mage from your graveyard to the battlefield
7. Repeat from step 3

Results

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