Echocasting Symposium + Time Walk + Timeless Witness

Echocasting Symposium

Time Walk

Timeless Witness

How it works

1. Cast Time Walk 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 Timeless Witness
4. When the Timeless Witness token enters, it triggers, returning Time Walk from your graveyard to your hand.
5. Repeat.