Echocasting Symposium + Walk the Aeons + Damage Control Crew
Echocasting Symposium
Walk the Aeons
Damage Control Crew
Infinite turnsLock
How it works
Cast Walk the Aeons by paying its mana cost, causing you to take an extra turn after this one.
Move to your next turn. At the beginning of your precombat main phase, Echocasting Symposium's paradigm ability triggers, causing you to cast a copy of it from exile.
Resolve the copy, creating a token copy of Damage Control Crew
When the Damage Control Crew token enters, it triggers, returning Walk the Aeons from your graveyard to your hand.