Stealth Dragon, Shiranui

:[Discard a card from your hand], search your deck for up to one "Demon Stealth Dragon, Shiranui "Oboro"", ride it as , and shuffle your deck. :When it attacks a vanguard, if you have a vanguard with "Shiranui" in its card name, this unit gets +10000 until end of turn. Then, at the end of that battle, [put this unit into your soul], draw a card, choose up to one of your opponent's rear-guards, and return it to his or her hand. If it was returned, your opponent chooses a card from his or her hand, and discards it.