Echocasting Symposium + Time Warp + Damage Control Crew

Echocasting Symposium

Time Warp

Damage Control Crew

How it works

1. Cast Time Warp by paying its mana cost, causing you to take an extra turn after this one.
2. 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.
3. Resolve the copy, creating a token copy of Damage Control Crew
4. When the Damage Control Crew token enters, it triggers, returning Time Warp from your graveyard to your hand.
5. Repeat.