Excava, the Risen Past + Second Chance + Solemnity

Excava, the Risen Past

Second Chance

Solemnity

How it works

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. It triggers, returning Second Chance from your graveyard to the battlefield. It won't enter with a finality counter due to Solemnity.
3. Repeat each turn.