Phantom Train, Graceful Reprieve, and Dualcaster Mage

Prerequisites

• Phantom Train on the battlefield
• Graceful Reprieve in hand
• Dualcaster Mage in hand
• available

Steps

1. Cast Graceful Reprieve by paying its mana cost
2. Holding priority, cast Dualcaster Mage by paying its mana cost
3. When Dualcaster Mage enters, it triggers, copying Graceful Reprieve, with the copy targeting Dualcaster Mage
4. Resolve the copy of Graceful Reprieve
5. Holding priority, activate Phantom Train by sacrificing Dualcaster Mage
6. When Dualcaster Mage dies, Graceful Reprieve triggers, returning Dualcaster Mage from your graveyard to the battlefield
7. Repeat from step 3
8. Resolve all Phantom Train abilities from step 5

Results

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