When Gyruda ability mills cards include Progenitus, milled cards move to graveyard face-down and Progenitus becomes revealed. then, I become can't do anything except concede until time-up, and tens of seconds later, Game Client becomes crashed. then, I reboot Game Client and return to game, curiously enough Progenitus is in battlefield. I think, Gyruda can't find Progenitus because Progenitus return to library (Hidden Zone) instead of moving to graveyard.