Fighting Emperor Dragon, Merciless Dragon

-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. :When your rear-guard by a card's ability, [ 1 & discard two cards from your hand], this unit, and if it is your main phase, attack your opponent's vanguard with this unit. :At the end of the battle this unit attacked, this unit gets drive -1 until end of turn.