I'll give some advice.
Alakazam: A good strategy, but why no Speed EVs? Alakazam is one of the fastest Psychics in the game, use his speed to your advantage. Try this: Timid Nature(+Spe, -Atk) and this EV spread: 252 SpA/ 252 Spe/ 6 HP.
Shedinja: Hmm, the chances of this guy living long are slim. Entry hazards almost instantly kill him, leech seed, weather, and super effective attacks which includes rock, flying, ghost, fire, and dark. Though wonder guard is a good ability, it can definitely be outsmarted. Besides, an opponent that can't hurt your shedinja isn't just going to stay in and die. Their going to switch out and kill your little bug. Wanna wall? I've got one for you.
Metagross(U)@Leftovers
Trait:Clear body
Nature:Calm(+SpD, -SpA)
EVs: 252 HP/ 252 SpD/ 6 Atk
-Toxic
-Reflect
-Light Screen
-Meteor Mash/Bullet Punch
Here you have somebody who can live many attacks, has few weaknesses, and cannot be outdone with toxic. He provides great support.
Umbreon: No matter how many EVs you invest in this guy, he's not going to be a great attacker. If you look at his stats, you'll see that he has wonderful defense/special defense.
Though your set is strong, lets make this guy a REAL tank.
Umbreon(F)@Leftovers
Ability: Synchronize
Nature:Careful(+SpD, -SpA)
EVs: 252 HP/ 252 SpD/ 6 Def
-Confuse Ray
-Toxic
-Curse
-Payback
With this set you can set up while the opponent is confused. He's already a special wall, and once you get up enough curses, he'll be nearly impenetrable by attacks.
Weavile: Attract is original! I really like the idea... but, while the opponent is madly in love with Weavile, maybe you could set up! Why don't you replace Arial Ace (which is SUPER weak, you won't be staying in against fighting types anyway) and give him Swords Dance! While the foe is in love, you'll be getting ready to sweep. Oh, and, maybe give him a focus sash instead of a razor claw so he can live ONE hit. You're also going to probably want to give him a Jolly nature (+Spe, -SpA) with these EVs: 252 Atk/ 252 Spe/ 6 HP, it's probably a typo, but you gave this guy 6 special attacking EVs :\
Musharna: Umm, you don't need two Psychic type moves. Get rid of psychic, since you've got dream eater and you plan on having your foe asleep. In place of Psychic you could throw in shadow ball for more coverage. If you wanted this guy to be bulky, you've got to give him HP EVs, as they provide more bulk than defense EVs. So use this spread: 252 HP/ 252 SpA/ 6 Def.
Dusknoir: Ehh? Why'd you give him a modest nature? Adamant(+Atk, -SpA) will work better, seeing he is a physical attacker. The EV spread to make him more bulky would be: 252 HP/ 252 SpD/ 6 Atk. You're probably wondering why I didn't give him any Def EVs. The answer is Will-O-Wisp. You already have (If you used my advice) 2 pokemon with toxic on your team. Will-O-Wisp halves the opponents attack, so you won't need as much defense. You can probably exclude protect and put in Shadow Sneak, since this guy can take a hit. Also, just give him leftovers. I'm assuming you want this guy to have somewhat of a good attack because otherwise you should go with Dusclops@Eviolite.
Hope I helped!