Ephemerate, Skullwinder, and Time Walk

Prerequisites

• Ephemerate in hand
• Skullwinder on the battlefield
• Time Walk in hand
• each turn available

Steps

1. Cast Time Walk by paying its mana cost, causing you to take an extra turn after this one
2. Cast Ephemerate by paying , blinking Skullwinder and exiling Ephemerate
3. When Skullwinder enters, it triggers, returning Time Walk from your graveyard to your hand
4. Move to your next turn
5. At the beginning of your upkeep, Ephemerate's rebound ability triggers, causing you to cast it from exile without paying its mana cost
6. Resolve Ephemerate, blinking Skullwinder
7. When Skullwinder enters, it triggers, returning Ephemerate from your graveyard to your hand
8. Repeat

Results

• Infinite turns
• Lock