Time Warp + Seasons Past + Demonic Tutor

Time Warp

Seasons Past

Demonic Tutor

How it works

1. Cast Seasons Past by paying 4, returning Beseech the Queen, Time Warp, and any number of cards with different mana costs to your hand and putting Seasons Past on the bottom of your library.
2. Cast Demonic Tutor by paying 1, putting Seasons Past from your library into your hand.
3. Cast Time Warp by paying 3, granting you an extra turn.
4. Repeat each turn.