My Pokemon Team

[X-Tyranitar]

INTRO
So I've recently purchased Pokemon Y and want to get back into competitive battling when I finish the game. So far I've been using "Pokemon Online" to find Pokemon I like and want to use. So here are the Pokemon I'd really like to use and there stats.​

Tyranitar @Tyranitarite (Lead)
Ability: Sand Stream
Nature: Careful
16 Hp/ 24 Atk/ 252 Def/ 216 SpDef
Movepool
Stealth Rocks
Thunder Wave
Stone Edge
Ice Punch/ Thunder Punch

Tyranitar is a necessity, feel free to suggest a different setup, but I must use Tyranitar. (;

And

Noivern @Life Orb (Special Sweeper)
Ability: Infiltrator
Nature: Timid
16 Hp/ 240 SpAtk/ 252 Spe
Movepool
Draco Meteor
Air Slash
Flamethrower
Boomburst

Noivern isn't entirely an absolute must but I really want to use him, and I think he has good synergy with Tyranitar. I think if I weren't to use him that I'd have to use Hydeigon though.

And

Sylveon @Leftovers (Cleric)
Ability: Cute Charm
Nature: Bold
80 Hp/ 252 Def/ 176 SpAtk
Movepool
Wish
Protect
Heal Bell
Moon blast

Alright, so Sylveon is a Pokemon I also really want to use. I really want to use a fairy type, and I think Sylveon is probably my favorite and best in my opinion.

So, now that I look at my team so far, I realize I need a Physical Sweeper, a Wall, and just another filler to throw off the opponent. Probably another Mega evolution besides Tyranitar.
So what I hope to achieve from this thread is advice on what I have, and good Pokemon choices for what I don't have.
Thanks for your help! (:

 

[PlatinumDude]

Tyranitarite only sees use on Dragon Dance Tyranitar, because of Mega Tyranitar's increased Speed. Lead Tyranitar is better off with Leftovers or Assault Vest:
-Stone Edge/Rock Slide
-Crunch
-Pursuit
-Fire Blast/Stealth Rock
Nature: Sassy/Careful
EVs: 252 HP/4 Atk/252 SDef
Item: Assault Vest/Leftovers
Ability: Sand Stream

or
-Dragon Dance
-Stone Edge
-Crunch
-Earthquake/Ice Punch
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Tyranitarite
Ability: Sand Stream

Life Orb Noivern needs Roost for recovery or U-turn for scouting purposes. Boomburst, while powerful, doesn't give Noivern any noteworthy coverage. Air Slash is also weak compared to Hurricane (which Noivern should use on Choice sets). Why does Noivern have 16 HP EVs? It needs all the power and Speed it can get:
-Draco Meteor
-Flamethrower
-Focus Blast
-Switcheroo/U-turn/Hurricane
Nature: Naive/Timid
EVs: 4 Atk/252 SAtk/252 Spe
Item: Choice Specs
Ability: Frisk/Infiltrator

or
-Draco Meteor
-Flamethrower
-Focus Blast
-U-turn/Roost
Nature: Naive/Timid
EVs: 4 Atk/252 SAtk/252 Spe
Item: Life Orb
Ability: Frisk/Infiltrator

If you don't have access to Poke Bank, Moonblast + Cute Charm is still an acceptable combination on Sylveon. If this is a simulator, Hyper Voice + Pixilate is preferred:
-Wish
-Protect
-Hyper Voice
-Heal Bell
Nature: Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Pixilate

To fill in the few slots, you can use (Mega) Garchomp as a wall breaker (use Mega Garchomp if you're not using Mega Tyranitar, of course), Wash Rotom (to check bulky Waters) or Gourgeist/Ferrothorn as defensive Grass Pokemon:

Garchomp:
-Swords Dance
-Outrage/Dragon Claw
-Earthquake
-Fire Fang/Stone Edge
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Lum Berry/Yache Berry/Garchompite

or
-Draco Meteor
-Earthquake
-Fire Blast
-Stone Edge
Nature: Naughty
EVs: 224 Atk/32 SAtk/252 Spe
Item: Garchompite

Wash Rotom:
-Volt Switch
-Hydro Pump
-Will-o-Wisp
-Pain Split/Rest
Nature: Bold
EVs: 248 HP/216 Def/44 Spe
Item: Leftovers/Chesto Berry

or
-Volt Switch
-Hydro Pump
-Will-o-Wisp
-Pain Split/Thunderbolt
Nature: Modest
EVs: 228 HP/60 SAtk/220 Spe
Item: Leftovers

or
-Volt Switch
-Hydro Pump
-Hidden Power (Ice/Fire)/Thunderbolt
-Trick
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Choice Scarf

Gourgeist (Super Size):
-Will-o-Wisp
-Leech Seed
-Seed Bomb
-Shadow Sneak/Protect
Nature: Impish
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Frisk

Ferrothorn:
-Stealth Rock/Spikes
-Leech Seed
-Gyro Ball/Thunder Wave
-Power Whip/Protect
Nature: Relaxed
EVs: 252 HP/208 Def/48 SDef
Item: Leftovers
Ability: Iron Barbs