Time Sieve + Descent into Avernus + Blessed Sanctuary
Time Sieve
Descent into Avernus
Blessed Sanctuary
Infinite turnsLock
How it works
At the beginning of your upkeep, Descent into Avernus triggers, putting two descent counters on it, then causing each player to create a number of Treasure tokens equal to the number of descent counters on Descent into Avernus, and causing each opponent to be dealt an amount of damage equal to the number of descent counters on Descent into Avernus.
Activate Time Sieve by tapping it and sacrificing five Treasures, causing you to take an extra turn after this one.