Timesifter + Draco + Isochron Scepter + Pull from Eternity + Academy Ruins

Timesifter

Draco

Isochron Scepter

Pull from Eternity

Academy Ruins

How it works

1. Activate Isochron Scepter by paying 2 and tapping it, casting a copy of Pull from Eternity without paying its mana cost.
2. Resolve the copy of Pull from Eternity, putting Draco into your graveyard from exile.
3. Activate Academy Ruins' second ability by paying 1 and tapping it, putting Draco on top of your library from your graveyard.
4. Move to the next turn.
5. At the beginning of that turn's upkeep, Timesifter triggers, exiling the top card of each player's library, and causing you to take an extra turn after this one due to exiling the highest mana value card.
6. Repeat.