Wormfang Manta, Fortune, Loyal Steed, and Karn, Argent Defender

Prerequisites

• Wormfang Manta on the battlefield
• Fortune, Loyal Steed on the battlefield
• Karn, Argent Defender on the battlefield

Steps

1. Activate Fortune's saddle ability by tapping the creature you want to blink, saddling Fortune
2. Declare Fortune as an attacker, attacking a player who cannot kill it in combat
3. When Fortune attacks, it triggers, creating a delayed triggered ability
4. At end of combat, Fortune's delayed triggered ability resolves, blinking it and Wormfang Manta
5. When Wormfang Manta leaves the battlefield, its second ability triggers, causing you to take an extra turn after this one
6. Wormfang Manta entering does not cause its abillity to trigger due to Karn
7. Repeat each turn

Results

• Infinite turns
• Lock