River Song, Kylox's Voltstrider, and Time Stretch

Prerequisites

• River Song on the battlefield
• Kylox's Voltstrider on the battlefield
• Time Stretch in hand
• An opponent cannot block and kill Kylox's Voltstrider
• each other turn available

Steps

1. Cast Time Stretch by paying , causing you to take two extra turns after this one
2. Move to your second extra turn
3. Activate Kylox's Voltstrider's first ability by exiling Time Stretch from your graveyard, causing Kylox's Voltstrider to become an artifact creature until end of turn
4. Declare Kylov's Voltstrider as an attacker
5. Kylox's Voltstrider triggers, causing you to pay to cast Time Stretch from exile
6. Resolve Time Stretch, causing you to take two extra turns after this one, and put Time Stretch on the bottom of your library
7. Move to your first extra turn, drawing Time Stretch from the bottom of your library due to River Song
8. Move to your second extra turn
9. Repeat

Results

• Infinite turns