Supreme Heavenly Emperor Dragon, Dragonic Overlord "The Purge"

-Stride Step-[Choose one or more cards with the sum of their grades being 3 or greater from your hand, and discard them] this card on your from face down. :[Choose a face down card from your G zone, turn it face up, choose a card with "Overlord" in its card name from your hand, and put it into your soul], if the number of cards in your opponent's damage zone is four or less, choose one of your opponent's vanguards, and deal one damage. During that damage check, all trigger effects are nullified. :This unit has the same number of drive as the number of cards in your opponent's damage zone.