Medomai the Ageless, Identity Thief, and Crystal Shard

Prerequisites

• Medomai the Ageless on the battlefield
• Identity Thief on the battlefield
• Crystal Shard on the battlefield
• Identity Thief does not have summoning sickness
• Opponents can not block and kill Identity Thief
• each turn available

Steps

1. Declare Identity Thief as an attacker
2. Identity Thief triggers, exiling Medomai the Ageless, becoming a copy of it until end of turn and Return Medomai from exile to the battlefield at end of turn
3. Deal combat damage with Identity Thief, causing you to take an additional turn after this one
4. Activate Crystal Shard by paying and tapping it, returning Identity Thief from the battlefield to your hand
5. Cast Identity Thief by paying
6. At the beginning of your end step, Identity Thief triggers, returning Medomai from exile to the battlefield
7. Pass the turn
8. Repeat

Results

• Infinite turns