Brainstorm, God-Eternal Kefnet, Isochron Scepter, and Walk the Aeons

Prerequisites

• Brainstorm in exile
• God-Eternal Kefnet on the battlefield
• Isochron Scepter on the battlefield
• Walk the Aeons in hand
• plus available each other turn available

Steps

1. During the end step before your turn, activate Isochron Scepter by paying and tapping it, casting a copy of Brainstorm without paying its mana cost
2. Resolve Brainstorm, causing you to draw three cards and put Walk the Aeons and another card on top of your library, ensuring Walk the Aeons is the topmost card
3. Move to your turn, drawing and revealing Walk the Aeons during your draw step
4. God-Eternal Kefnet's first ability triggers, causing you to pay to cast a copy of Walk the Aeons
5. Resolve the copy of Walk the Aeons, causing you to take an extra turn after this one
6. Activate Isochron Scepter by paying and tapping it, casting a copy of Brainstorm without paying its mana cost
7. Repeat from step 2

Results

• Infinite turns