Storm Dominator, Commander Thavas

-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 "Storm Dominator, Commander Thavas" from your G zone, and turn it face up] Choose up to one of your rear-guards, until end of turn, it gets +5000 and ":This unit can attack from the back row.", and until end of turn, this unit gets "Wave‐4th time only:When your unit attacks a vanguard, choose three of your opponent's rear-guards, your opponent chooses one rear-guard from among them, and retires it.".