Echocasting Symposium + Temporal Manipulation + Greenwarden of Murasa

Echocasting Symposium

Temporal Manipulation

Greenwarden of Murasa

How it works

1. Cast Temporal Manipulation 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 Greenwarden of Murasa
4. When the Greenwarden of Murasa token enters, it triggers, returning Temporal Manipulation from your graveyard to your hand.
5. Repeat.