Excava, the Risen Past, Second Chance, and Solemnity

Prerequisites

• Excava, the Risen Past on the battlefield
• Second Chance on the battlefield
• Solemnity on the battlefield

Steps

1. At the beginning of your upkeep, Second Chance triggers, causing you to sacrifice it and get an extra turn after this one
2. Declare Excava as an attacker
3. It triggers, returning Second Chance from your graveyard to the battlefield
4. It won't enter with a finality counter due to Solemnity
5. Repeat each turn

Results

• Infinite turns
• Lock