I don't see how NP houndoom is any sort of huge problem. Clefable walls it to an extent, and Mismagius can take it out with HP fighting. Also, with the amount of spikes and SR up on the field, Entei can probably take it down with one ESpeed (I'll have to calc that).
WRONG. NP HOUNDOOM RIPS THROUGH THIS TEAM.
First of all, Houndoom sees many chances to set up, walling Spiritomb's entire moveset, and 3/4 of Sceptile's, and there's always Focus Blast's accuracy problem.
Secondly, Clefable does anything but wall +2 Houndoom's STAB Fire Blast (don't even think about it if it has the Flash Fire boost from Spiritomb). Houndoom's +2 STAB F-Blast does a minimum of 102.3% to Clefable. No kidding. If you switch to Mismagius when it grabs the NP boost, your Mismagius does outspeed it, but your HP Fighting does a maximum of 64.4% to Houndoom, then it KO's you with Dark Pulse.
Lastly, you say Entei can revenge it with ESpeed. Okay, its true, but only if it has taken AT LEAST 39.4% damage, and at most it needs to take 48.6% damage.
It has insane special attack and speed stats so it acts as perfect contender for this job.
Its special attack and speed stats are not insane, 105 base each, maximum of 339 each, but not both.
It has great special defense
Clefable's Sp.Def stat is base 90, 306 at most.
However, Moltres is a big threat to him, then again Moltres is a big threat to a lot of leads. So whatever.
You make it sound as if it doesn't matter. And then it proceeds to sweep the majority of your team bar Spiritomb. So whatever.
The lack of HP is concerning but thanks to Pain Split that's not a huge deal.
Pain Split doesn't increase your base HP...
It heals, but only if you have less HP then your opponent.