My competitive OU team.. Is it good?

This is my team(exported from Pokemon showdown)

Ninjask (M) @ Choice Scarf
Trait: Speed Boost
EVs: 255 SAtk / 255 Spd
Hasty Nature
- Bug Buzz
- Shadow Ball
- Slash
- Baton Pass

Cloyster (M) @ Leftovers
Trait: Shell Armor
EVs: 255 Def / 255 SAtk
Bold Nature
- Aqua Ring
- Hail
- Toxic Spikes
- Blizzard

Spiritomb (M) @ Chesto Berry
Trait: Infiltrator
EVs: 255 SAtk / 255 SDef
Gentle Nature
- Hypnosis
- Nightmare
- Dream Eater
- Rest

Landorus-T (M) @ Earth Plate
Trait: Sheer Force
EVs: 255 Atk / 255 Spd
Adamant Nature
- Earthquake
- Sludge Wave
- Psychic
- Rock Polish

Gallade (M) @ Razor Claw
Trait: Steadfast
EVs: 255 Atk / 255 Spd
Adamant Nature
- Zen Headbutt
- Close Combat
- X-Scissor
- Leaf Blade

Is it good? What would you change? EDIT i just noticed that theyve changed genesect to ubers :/ So how should the last pokemon be?

First off, Ninjask needs an item over Choice Scarf clearly since it locks you into a single move which is really not good for something like Ninjask now. Focus Sash or Leftovers should do the trick while changing the nature to Impish and giving it this moveset.

Protect
Baton Pass
Swords Dance
X-Scissor (To prevent being Taunt bait.)

Cloyster should also have a Naive nature along with a Life Orb with this moveset. It's also a monster with the Skill Link ability.

Shell Smash
Icicle Spear
Rock Blast
Surf/Hydro Pump

And for Landorus I'd replace Sludge Wave and Psychic with HP Ice and Stone Edge. A Naive nature also helps making it faster.

Sorry the post was so small but I hope it helps, gl dude.

Thanks for the advice, so far my team is now...

Shedinja @ Focus Sash
Trait: Wonder Guard
EVs: 252 Spd / 252 Atk / 4 SDef
Jolly Nature
- X-Scissor
- Shadow Claw
- Confuse Ray
- Aerial Ace

Cloyster (M) @ Life Orb
Trait: Skill Link
EVs: 252 Spd / 252 Atk / 4 SAtk
Naive Nature
- Shell Smash
- Icicle Spear
- Rock Blast
- Hydro Pump

Spiritomb (M) @ Chesto Berry
Trait: Infiltrator
EVs: 255 SAtk / 255 SDef
Gentle Nature
- Hypnosis
- Nightmare
- Dream Eater
- Rest

Weezing (M) @ Leftovers
Trait: Levitate
Shiny: Yes
EVs: 252 SDef / 252 HP / 4 SAtk
Calm Nature
- Will-O-Wisp
- Fire Blast
- Pain Split
- Thunderbolt

Landorus-Therian (M) @ Earth Plate
Trait: Intimidate
EVs: 252 Spd / 252 Atk / 4 SAtk
Naive Nature
- Earthquake
- Hidden Power [Ice]
- Stone Edge
- Rock Polish

Gallade (M) @ Razor Claw
Trait: Steadfast
EVs: 255 Atk / 255 Spd
Adamant Nature
- Zen Headbutt
- Close Combat
- X-Scissor
- Leaf Blade

Good?

For one, Shedinja needs loads of team support to work, ie Rapid Spin support to keep hazards off the field because it dies in a single switch in when Stealth Rock is on the field. The widespread use of sandstorm and hazards makes Shedinja nigh unusable in OU. Scizor should see some use:
-U-turn
-Bullet Punch
-Superpower
-Pursuit/Quick Attack
Nature: Adamant
EVs: 248 HP/252 Atk/8 Spe
Item: Choice Band
Ability: Technican

Or
-Swords Dance
-Bullet Punch
-Bug Bite
-Superpower/Brick Break
Nature: Adamant
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb
Ability: Technician

Or
-Swords Dance
-Bullet Punch
-Superpower/Bug Bite
-Roost
Nature: Adamant
EVs: 252 HP/40 Atk/216 SDef
Item: Leftovers
Ability: Technician

White Herb or Focus Sash are also worth considering on Cloyster, the former for negating the defensive drops of Shell Smash and the latter for ensuring that Shell Smash is executed.

Gentle nature = bad. It doesn't do anything competitively useful. Use Gengar as an offensive Ghost:
-Shadow Ball
-Focus Blast
-Substitute
-Disable/Thunderbolt/Hidden Power Fire/Pain Split
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Black Sludge/Life Orb

or
-Shadow Ball
-Focus Blast
-Hidden Power (Fire)
-Substitute/Protect
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Black Sludge/Life Orb

Or use Sableye or Jellicent as defensive Ghosts:

Sableye:
-Taunt
-Will-o-Wisp
-Recover
-Night Shade/Foul Play
Nature: Careful/Calm
EVs: 252 HP/120 Def/136 SDef
Item: Leftovers
Ability: Prankster

Jellicent:
-Scald/Surf
-Will-o-Wisp/Toxic
-Recover
-Taunt
Nature: Bold
EVs: 248 HP/216 Def/44 Spe
Item: Leftovers

Or
-Scald/Surf
-Will-o-Wisp/Toxic
-Recover
-Shadow Ball/Ice Beam
Nature: Calm
EVs: 252 HP/36 Def/220 SDef
Item: Leftovers
Ability: Water Absorb

Or
-Water Spout
-Hydro Pump/Surf/Scald
-Shadow Ball
-Ice Beam/Giga Drain
Nature: Modest
EVs: 172 HP/252 SAtk/84 Spe
Item: Choice Specs
Ability: Water Absorb

Ferrothorn is a better alternative over Weezing because of its typing and resistances:
-Spikes/Stealth Rock
-Leech Seed
-Power Whip
-Gyro Ball/Thunder Wave/Protect
Nature: Relaxed
EVs: 252 HP/88 Def/168 SDef
Item: Leftovers

Even though Gallade is my favorite Pokémon, I hate to say that it doesn't see much use in OU because base 80 Speed is just too average for a sweeper. Lucario should suffice, since its typing compensates for its low defenses:
-Swords Dance
-Close Combat
-ExtremeSpeed
-Crunch/Ice Punch/Bullet Punch
Nature: Adamant/Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Life Orb

Hows this?

Scizor (M) @ Life Orb
Trait: Technician
EVs: 8 Spd / 252 Atk / 248 HP
Adamant Nature
- Bullet Punch
- U-turn
- Superpower
- Bug Bite

Cloyster (M) @ White Herb
Trait: Skill Link
EVs: 252 Spd / 252 Atk / 4 SAtk
Naive Nature
- Shell Smash
- Icicle Spear
- Rock Blast
- Hydro Pump

Gengar (M) @ Black Sludge
Trait: Levitate
Shiny: Yes
EVs: 252 Spd / 252 SAtk / 4 HP
Timid Nature
- Shadow Ball
- Focus Blast
- Substitute
- Pain Split

Ferrothorn (M) @ Leftovers
Trait: Iron Barbs
EVs: 88 Def / 252 HP / 168 SDef
Relaxed Nature
IVs: 0 Spd
- Stealth Rock
- Leech Seed
- Power Whip
- Gyro Ball

Landorus-Therian (M) @ Earth Plate
Trait: Intimidate
EVs: 252 Spd / 252 Atk / 4 SAtk
Naive Nature
- Earthquake
- Hidden Power [Ice]
- Stone Edge
- Rock Polish

Lucario (M) @ Life Orb
Trait: Steadfast
EVs: 252 Spd / 252 Atk / 4 HP
Jolly Nature
- Swords Dance
- Close Combat
- ExtremeSpeed
- Crunch

Life Orb is the preferred item if Gengar is using Pain Split because when Gengar's HP gets too low because of Sub and LO recoil, Pain Split can potentially restore a lot of HP for Gengar.

Also, your current Scizor set should use Choice Band because it's meant to scout. Use Pursuit or Quick Attack over Bug Bite, since they have their utility.

Sainan said:

Landorus-Therian (M) @ Earth Plate
Trait: Intimidate
EVs: 252 Spd / 252 Atk / 4 SAtk
Naive Nature
- Earthquake
- Hidden Power [Ice]
- Stone Edge
- Rock Polish

Click to expand...

Much like Gengar, Landorus-T likes having Life Orb to help it sweep better. Also, a Naive nature is somewhat moot when you have Rock Polish so Naughty or Adamant is generally better.