Conquering Supreme Dragon, Voltech Zapper Dragon (RRR)

[Stride]-Stride Step-[Choose one or more cards with the sum of their grades being 3 or greater from your hand, and discard them] Stride this card on your (VC) from face down.
[AUTO](VC)Thunderstrike 3 (This ability is active when your opponent's bind zone has three or more cards):When this unit attacks a vanguard, until end of that battle, this unit gets [Power]+10000, and [AUTO](VC):[Counter Blast (1)] At the end of the battle, you may pay the cost. If you do, for every two cards in your opponent's bind zone, your opponent chooses one of his or her rear-guards, retires it, and binds that card face up..