Progenitor Mimic + Temporal Manipulation + Mnemonic Wall

Progenitor Mimic

Temporal Manipulation

Mnemonic Wall

How it works

1. Cast Temporal Manipulation by paying its mana cost, taking an extra turn after this one.
2. At the beginning of your next upkeep, Progenitor Mimic triggers, creating a token copy of Mnemonic Wall.
3. When the token Mnemonic Wall enters the battlefield, it triggers itself, returning Temporal Manipulation from your graveyard to your hand.
4. Repeat.