Medomai the Ageless, The Wondrous Wasp, and Phelia, Exuberant Shepherd

Prerequisites

• Medomai the Ageless on the battlefield
• The Wondrous Wasp in hand
• Phelia, Exuberant Shepherd on the battlefield
• the first turn available

Steps

1. Deal combat damage using Medomai, triggering its ability, causing you to take an extra turn after this one
2. Cast The Wondrous Wasp by paying
3. When The Wondrous Wasp enters, it triggers, tapping Medomai and causing it to lose all its abilities until The Wondrous Wasp leaves the battlefield
4. Move to your next turn
5. Declare Medomai and Phelia as attackers
6. Phelia triggers, exiling The Wondrous Wasp until your end step
7. This will also cause Medomai to regain its abilities
8. Deal combat damage using Medomai, triggering its ability, causing you to take an extra turn after this one
9. At the beginning of your end step, Phelia triggers, returning The Wondrous Wasp from exile to the battlefield
10. Repeat from step 3

Results

• Infinite turns
• Lock