allright. before I get started, your badly written bump was made 3 hours after you posted the team. it's supposed to be 24 hours. be patient.
now that that's out of the way, I agree with DFA on quite a bit of stuff. dragonite is way too bulky to properly utilize focus sash. he'll be taking more than one hit, and after he takes the first one, sash is useless. you'll be much better off using a yache or lum berry, or even a life orb. absolutely no choice specs on weezing. he's your just about only answer to physical threats barring insane prediction with gyara's intimidate coming in on nve moves, which is hampered greatly by stealth rock and lack of defensive ev's. speaking of stealth rock, you've got 3 pokemon weak to it and no resists. weavile's sash is ruined by stealth rock. replace the sash with an expert belt or a choice band, as sashed weavile is only really viable on the swords dance lead set, where life orb is probably more viable anyways. gyara's ability to sweep is greately hampered by stealth rock, especially since he's going to be hit pretty hard without any defensive or hp ev's. taking away a quarter of his health per switch in is not something that you're going to like. by the looks of it, you've got
tyranitar problems as well. without lefties recovery, stealth rock is going to hit gyara that much harder. you've got no way to deal with tyraniboah, who can kill your whole team without much trouble if he runs boltbeam. your best answer is weavile, who can't switch in on sub or focus punch. he's also going to take a lot from thunderbolt. moving on,
specs shaymin will kill everything on this team if he has hp ice, and everything except nite if he has the standard hp fire. you have some guys who can kill it, but nobody who can reliably switch in. 'nite can come in on those who pack hp fire, but nobody likes taking any specs attacks, especially without recovery and a stealth rock weakness. you also happen to be weak to
lucario. the swords dancing variant can kill this whole team with stealth rock support in one or two hits except maybe weezing, who is pretty easy to dispatch considering the fact that you carry explosion and possibly even choice specs and that he lacks reliable recovery. but then we look at specsluke and the problems double. he kills the whole team without set-up, and you have no means of reliably revenge killing him, as he outspeeds all but two of your pokemon, and he can switch out of them. nobody can switch in, so every time lucario comes out, just about another pokemon dies if he predicts well. you can predict around it, but as a few pokemon die, this becomes exceedingly hard. standard dd
salamence with one dance can sweep this whole team with stealth rock support, and everybody except blissey dies to the specs one, but after blissey is gone, you have nobody who wants to switch into a draco meteor. nobody can really switch into a mixmence draco meteor, as blissey dies to brick break and then you have the same problem. moving on to
gengar. nobody can switch into a specs gengar, but the lo variant will give you problems, as blissey won't take focus blasts forever and if she's your last pokemon, can't do jack squat back to gengar. nobody likes sleep on this team, which is something gengar packs. just about everybody except blissey dies to one of gengars common attacks. timid gengar outspeeds everyone on this team except weavile, who doesn't enjoy switching in on a focus blast while not being able to pursuit gengar anyways.
scarfchomp runs through this team like an angry child with a pair of scissors. starmie can switch into outrage and then kill, but weavile can't switch in. those are your two ways of killing garchomp, and neither of them can really switch in. sd yache chomp kills this team once one of them is gone.
dugtrio, while nobody can really "counter" him, takes out blissey and starmie, which are important to cover many of the threats I've already listed. shoice specs or scarf
porygon-z absolutely rapes this team beyond belief once blissey is dead. resttalk
machamp just about walls this team barring starmie's psychic while being able to take out many pokemon with dynamicpunch/ice punch, though gyara can take this well. if he has stone edge or thunderpunch, you're screwed. if he comes in on a starmie locked into ice beam or thunderbolt, somebody is going to die. if you let
curselax get in one or two curses, even weavile's brick break isn't going to do too much to it while it can just about kill everyone, since you lack a phazer or strong stab fighting move.
zapdos can kill off most of this team while only having to fear ice punch from weavile who is killed by thunderbolt. bulky zapdos stalls this team with roost or resttalk while nobody can do too much to it.
cresselia, who can also run charge beam/ice beam with resttalk absolutely walls and kills your team. gyarados can come in on 'cune, but he doesn't like repeated boosted ice beams, espeically if he cam in on stealth rock.
yanmega doesn't like blissey, but can sweep this team otherwise. the reversal set kills everyone without too much trouble. you've got quite a few gaping holes to common pokemon. let's review:
tyranitar
shaymin
lucario
salamence
gengar
garchomp
dugtrio
porygon-z
machamp
snorlax
zapdos
cresselia
yanmega
those are a lot of common pokemon, and they all give you very big problems. I'm just about sure you didn't look at the threat list provided by jumpman, and you should do that with every team you make. now, I can try to help you deal with all those, but it's quite hard to help you cover that many pokemon without completely changing the team. first of all, dragonite is a mediocre lead at best, and it doesn't look like it'll be doing much after that. replacing him with
Metagross @ Choice Scarf
Adamant
252 attack, 228 speed, 24 hp
~ Meteor Mash
~ Ice Punch
~ Pursuit
~ Earthquake
the ev's hit 384 speed, outspeeding jolly weavile. this guy helps you a lot. He gives you a switch to tyraniboah and cb ttar barring earthquake. metagross can easily kill tyranitar with stab SE meteor mash. this makes your
shaymin weakness a bit more apparent, but it gives you a reliable pokemon that can kill shaymin in one turn with ice punch. metagross can switch into specs lucario without dying and sd lucario without the boost (come in as he swords dances), and can outspeed and respond with earthquake for the ohko. if someone has already taken the sleep, gengar can come in on just about anything and pursuit gengar to his grave no problem. metagross doesn't counter garchomp, but he has 130 base defense and resists outrage, so any garchomp locked into outrage dies to ice punch without even the chance to switch. metagross has the same problems with duggy as he has with garchomp, but if duggy is locked into anything other than earthquake, metagross can come in and force a switch, making the opponent have to predict perfectely to not lose a pokemon. metagross resists tri attack and ice beam while being able to kill porygon-z with meteor mash no problem. this makes him a pretty good switch to anything z tries to hit you with. nobody enjoys confusion, but gross can take everything else with his beefy defense and hp while being able to hit back with meteor mash, which is something that machamp doesn't like too much. though the fire blasting machamps can hit metagross hard, so I wouldn't rely on gross or switch him in immediately.
machamp is still a threat.
curselax still poses problems, but if he doesn't pack fire punch, metagross doesn't take too much from his attacks. metagross is not only good physically defensively, but also specially, so he can hit zapdos harder with ice punch than zapdos can hit him with thunderbolt.
cressy doesn't enjoy meteor mashes, but she can throw up a reflect or thunderwave, neither of which metagross enjoys. yanmega can take an ice punch from metagross but dies to two, so that's good. bug buzz, in the meantime, won't kill you at the same rate without some form of a boost.
now, scarf metagross makes a much better lead than dragonite, being able to outspeed common lead pokemon and kill them. he also boasts pursuit, which makes him able to tell gengar, non-scarf azelf, and any other assorted pursuit-weak leads to go die. there are, however, problems with metagross. he opens up a rather large heatran weak that dragonite was (kind of) able to solve. metagross can't switch in on fire blast or earth power. gyarados at this point can't solve anything about heatran without defensive help. so let's look at some of the big threats now.
shaymin
cressy
machamp
snorlax
this list is much smaller than the last one, however, so we're doing good. so, what other pokemon aren't really doing much for the team? metagross does a lot of the things that weavile does, so we can probably replace him. let's see... an great smogon user named yagami light, or light, made a set for a nidoking, dubbed Crushking, to be used in OU that can "crush" walls. let's see, it
does help you against a lot of these guys. let's take a look
Nidoking @ Life Orb
Lonely
252 attack, 174 special attack, 84 speed
~ Fire Blast
~ Ice Beam
~ Megahorn
~ Earthquake
super in depth information on crushking can be found
here. crushking can switch in on electric attacks, which you have two weaknesses to, which is a very important big thing about him. he also resists fighting, which is nice. crushking can 2HKO cressy no problem with megahorn while cressy can't do too much back. crushking resists fighting attacks as well as stone edge (though gross can come in better on stone edge) and is immune to thunderpunch. he can hit back with megahorn on machamps weaker physical defense with his fully boosted high attack. if he packs ice punch, starmie can come in to kill him. this guy also gives you some insurance against heracross with a resistance to his stabs and close combat (though close combat still 2HKO's) and can hit back with fire blast. so now you're left weak to
shaymin
curselax
heatran
changing your gyarados to the resttalk version of gyara can help you to stall out shaymin's seed flare with a bit of luck, absorb sleep, and effectively counter heatran into the ground...here's the set.
Gyarados @ Leftovers
Adamant
252 hp, 96 attack, 80 defense, 60 special defense, 20 speed
~ Rest
~ Sleep Talk
~ Dragon Dance
~ Surf
this has the potential for sweeping late game as well. you have a reliable sleep absorber, gyarados is actually able to take hits from heatran for example, and even a bit from shaymin. this thing, with a few dd's is certainly a very bulky sweeper as well. now, of the pokemon I listed, you are only really weak to curselax. you aren't as worried about stealth rock anymore (two of your three weaknesses turned into resists), you have someone who can absorb toxic spikes, and you have a sleep absorber. What are you missing? A reliable phazer to take care of stuff like curselax that sets up in your face. so let's see. the most simple solution would be to put haze over explosion on weezing, as you'll be using explosion when you have low hp, which is also when you'll be using pain split. what you could also do to add a phazer is put in donphan over weezing.
Donphan @ Leftovers
Impish
252 hp, 252 defense, 4 attack
~ Roar
~ Earthquake
~ Ice Shard
~ Stealth Rock
this gives you a reliable phazer and access to stealth rock so that you can put ice beam on blissey, which is something that she really needs.
so you can change 'nite into scarfgross, made gyara the sleep-talker, turned weavile into crushking and put haze on weezing (or switched him to donphan to allow blissey to ice beam). that's all the advice I have to give for now.