Progenitor Mimic + Returned Pastcaller + Temporal Manipulation

Progenitor Mimic

Returned Pastcaller

Temporal Manipulation

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 Returned Pastcaller.
3. When the token Returned Pastcaller enters the battlefield, it triggers itself, returning Temporal Manipulation from your graveyard to your hand.
4. Repeat.