Phantom Steed, Walk the Aeons, and Mnemonic Wall

Prerequisites

• Phantom Steed on the battlefield
• Walk the Aeons in hand
• Mnemonic Wall in exile
• An opponent can not block Phantom Steed
• available

Steps

1. Cast Walk the Aeons, taking an extra turn after this one
2. Attack with Phantom Steed
3. Phantom Steed triggers, creating a token copy of Mnemonic Wall that is tapped and attacking
4. Mnemonic Wall enters, returning Walk the Aeons from your graveyard to your hand
5. Pass the turn
6. Repeat

Results

• Infinite turns