Six + Chromatic Sphere + Dakmor Salvage + Urza, Lord Protector

Six

Chromatic Sphere

Dakmor Salvage

Urza, Lord Protector

How it works

1. Cast Chromatic Sphere from your graveyard by paying 0 and discarding Dakmor Salvage.
2. Activate Chromatic Sphere by paying 1, tapping and sacrificing it, adding 1 and causing you to mill two cards and return Dakmor Salvage from your graveyard to your hand.
3. Repeat.