SM OU My Ou Team. Need advice on it.

[BigBoyTomathy]

My Ou team is fairly basic and generic, and any advice will be appreciated.

Mew @ Psychium Z
Ability: Synchronize
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Taunt
- Psyshock
- Toxic
- Aura Sphere

Tyranitar @ Assault Vest
Ability: Sand Stream
EVs: 252 HP / 252 Atk / 4 SpA
Naughty Nature
- Crunch
- Fire Blast
- Stone Edge
- Earthquake

Garchomp @ Yache Berry
Ability: Rough Skin
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Dragon Claw
- Earthquake
- Stealth Rock
- Stone Edge

Breloom @ Toxic Orb
Ability: Poison Heal
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Bullet Seed
- Rock Tomb
- Swords Dance
- Mach Punch

Kyurem-Black @ Leftovers
Ability: Teravolt
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Substitute
- Ice Beam
- Roost
- Earth Power

Swampert-Mega @ Swampertite
Ability: Swift Swim
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Waterfall
- Rain Dance
- Superpower
- Ice Punch

As I said, I am looking for advice as I am relatively new to the competitive scene. I put it into Pyrotoz and it had good coverage overall.

 

[Gross Sweep]

Welcome to Smogon! I'm locking your RMT for the time being as the forum rules require that you provide in-depth descriptions for each Pokemon to explain their roles. Please read the rules carefully and take a look at Team Showcase to see the level of detail we require. PM me with updated descriptions and I'll be happy to unlock this.