Time Walk + Seasons Past + Demonic Collusion

Time Walk

Seasons Past

Demonic Collusion

How it works

1. Cast Seasons Past by paying 4, returning Demonic Collusion, Time Walk, 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 Collusion by paying 3, putting Seasons Past from your library into your hand.
3. Cast Time Walk by paying 1, granting you an extra turn.
4. Repeat each turn.