RE: Help whit my deck!!!!
Houndoom Prime isn't the greatest pokemon to center a deck around but it can work, you just need a decent build.
As a stage 1 pokemon, Houndoom, both prime and regular holo gives you a few options for techs. With your current build i'm guessing you have Mandibuzz (assuming from B&W) and Tornadus are to counter {F} decks and just function as decent attackers. Now against some of the higher tier decks Houndoom won't be able to win one-on-one, so you need a way to hinder your opponent to give you enough time to set up and take a decent lead. Let me throw this list at you
4-2/2 Houndoom (2 holo / 2 Prime)
3-3 Weavile UD
1 or 2 Tornadus
1 Shaymin UL
1 Cleffa
Both Houndoom are the main attackers here. Weavile is here mainly for its poke-power to be able to look at your opponents hand, choose any card there and discard it. Using this power in combination with Seeker and Super Scoop Up give you multiple opportunities to discard vital cards from your opponents hand. This in turn can either slow down their set-up or just remove threats from their hand. Sneasel also functions as a decent-ish early game attacker if you're ever forced to use it. It can potentially deal upto 120+ damage. To add to the disruption you can play Lost Remover/Crush Hammer to mess with your opponents energy and cards like Judge and N to further mess with your opponents hand. Tornadus is still their to counter fighting decks. Shaymin helps to move energy around which has it's uses during a game if you want to transfer energy from a damaged Houndoom to a fresh Houndoom or Tornadus then switch them to save yourself a prize.