I'd recommend the following:
-Change Crunch to Dark Pulse, since it goes better with his higher special attack and gets boosted from the next move.
-Nasty Plot would make a good 3rd move; Nasty plot sharply boosts his special attack.
-For the last move, you could use Hidden power for Type coverage, but since yours in for In game, that might not be the easiest thing to do. You could have Sucker punch, which, while physical, can give Houndoom priority over fast targets. Will-O-Wisp is also good for crippling other pokemon.
These are just my suggestions, feel free to adjust them as you see fit.