ORAS OU First competitive team. Any advices?

[STRultimate]

This is my first competitive team that I built myself and therefore i'm fairly inexperienced in competitive.
This is why I wanted to bring this team that I built in my inexperience.


Charizard-Mega-X @ Charizardite X
Ability: Tough Claws
Level: 50
Shiny: Yes
EVs: 252 Atk / 4 SpA / 252 Spe
Naughty Nature
- Dragon Dance
- Dragon Claw
- Flare Blitz
- Double-Edge

Azumarill @ Choice Band
Ability: Huge Power
Level: 50
Shiny: Yes
EVs: 252 HP / 252 Atk / 4 Def
Adamant Nature
- Aqua Jet
- Waterfall
- Superpower
- Ice Punch

Raikou @ Leftovers
Ability: Pressure
Level: 50
Shiny: Yes
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Thunderbolt
- Calm Mind
- Substitute
- Hidden Power [Ice]

Landorus-Therian @ Assault Vest
Ability: Intimidate
Level: 50
Shiny: Yes
EVs: 252 HP / 124 Atk / 80 Def / 52 SpD
- Earthquake
- Stone Edge
- U-turn
- Knock Off

Jirachi @ Sitrus Berry
Ability: Serene Grace
Level: 50
Shiny: Yes
EVs: 240 HP / 160 Def / 76 SpD / 32 Spe
Impish Nature
- Wish
- Stealth Rock
- Thunder Wave
- Ice Punch

Spiritomb @ Sitrus Berry
Ability: Pressure
Level: 50
Shiny: Yes
EVs: 248 HP / 252 SpA / 8 SpD
Modest Nature
- Shadow Ball
- Dark Pulse
- Nasty Plot
- Protect

Any suggestions, including whole new pokemon are welcome.

Thank you :]