Wormfang Manta, Y'shtola Rhul, and Karn, Argent Defender

Prerequisites

• Wormfang Manta on the battlefield
• Y'shtola Rhul on the battlefield
• Karn, Argent Defender on the battlefield

Steps

1. At the beginning of your end step, Y'shtola Rhul triggers, blinking Wormfang Manta
2. When Wormfang Manta leaves the battlefield, its second ability triggers, causing you to take an extra turn after this one
3. Wormfang Manta entering does not cause its abillity to trigger due to Karn
4. Repeat each turn

Results

• Infinite turns
• Lock