That's true, so on second thought the deck should run more Hydreigon-EX to avoid prizing. If 2 Hydreigon-EX on the bench is going to be needed I would run a 3rd and drop Giratina-EX altogether. Then there is room for another card, like PFC, Shauna, Druddigon, Megaphone, etc.
I say you don't...