First off, there's a lot in this post that makes me think it's in-game. Our recommendations on Competitive RMT typically assume you're playing on a simulator, where entire teams can be changed at the touch of a button, and where you can change your Hidden Power types instantly.
Ninjask is meh. It's fragile, set-up fodder and 4x SR weak. That generally means that if your sweeper gets phazed or you have to switch (like if I sent my Chandelure against your Breloom), you've got no more BPer. It also means Ninjask will often get KO'ed before it can even pass. It's fast, yeah, but speed only really goes so far. As a general rule, you shouldn't run a Ninjask without a spinner since if SR gets up and stays up it will not make it in more than once. It's also kinda set-up fodder for Agility leads like Metagross.
Ursaring's biggest threats are physical, so why 252 SpD? move those to Def. Defensive Steel/Psychics (Jirachi and Metagross come readily to mind) can take anything Ursaring can deal and KO it with Hammer Arm (Metagross) or hax it to death (Jirachi). Metagross is a lot more dangerous since Rachi is usually used for SpD.
Substitute or Mach Punch over Facade for Breloom. Sub lets Breloom Spore, Sub and Focus Punch to its heart's content without needing more Spores. Mach Punch gives you Priority. Anything with Ice Shard can pick this off, as can ExtremeSpeed Dragonite very easily. The Sub or Priority will alleviate this problem to a degree.
Hydreigon's Charge Beam isn't a good idea for a Specs set. It's too weak to be locked into. Change it to Surf or Draco Meteor OR change the item to Life Orb.
Alakazam is better off using Hidden Power Ice or Fire over Grass Knot. It can also make great use of Subs. Grass Knot's coverage is meh (Ground, Rock and Water), and the damage is really unreliable. HP Ice hits Dragons and Gliscor, HP Fire deals with Steels (Ferrothorn and Forretress in particular) and opposing Scizor and Genesect (provided you're faster).
For Porygon-Z, GET HYPER BEAM OFF THAT THING. That move is awful. Your opponent can easily use the cooldown to set up and get an easy KO. Or you can be revenge-killed without fear at all. It just leaves you way too open to..... everything and any competent human opponent is going to take advantage of that. Hidden Power.... Well, in UU Fighting is a good option, but Fighting doesn't help as much in OU, which is where you'd have to play this team. HP Ground deals with Heatran, which could give you some trouble late-game. HP Ice and HP Fire are valid for the same reasons as with Alakazam, although you should not use the same one you give it. Finally, give it a Life Orb instead.
It's not a bad start, although you might want to remove the OU Pokemon (Hydreigon and Alakazam) so you can use this team in UU, where it'd do much better.
Last edited by loco1234; 29th November 2012 at 9:24 PM.
"Whether Castform the Weather Pokemon can weather the weather is dependent on whether the weather that it's weathering is the proper weather for it to weather. Whether the opponent can weather the weather is also subject to whether the weather that it's weathering is the right weather to weather. Whether Castform can weather the opponent is once again dictated by the weather and whether that weather is the favorable weather for weathering. But most importantly, you should know whether there will be weather to weather rather than what weather they will be weathering and whether they can weather that weather."
- Smogon's Castform analysis