Forum:Magcian of faith and shallow grave..OTK

OTK... 1.First activate mass driver and tribute a summoned magician of faith. 2.Activate shallow grave,special summon magician of faith face-down. 3.Flip magician of faith and return shallow grave. 4.Tribute magician of faith again for mass driver.

Is that possible??...or is there a rule I miss to make this OTK invalid?