Now that I think about it... HD really isn't that good of a deck anymore. It's just too slow. I've been playtesting different variants against stuff like terrakion, gartaria, Bulltwo, and eels, and it only wins about half of the matches due to prized hydreigons, rare candies, bad starts, and slow setups.
maybe you should try a variant with only these Pokémon:
Yes, I know its 100% vulnerable to Terrakion decks, but I have a crazy feeling that something weird like that would do well. I did the same thing with my Hammertime deck; turned it into a Straight Darkrai/Sableye deck with nothing else except Hammers. It actually beat up Gartaria and my Eels like a nerd on the street. :D (terrible analogy, I know. I really suck at those.)