Need Help

[NexGenHatred]

My team is great, it's gotten me past 1800 ELO multiple times. Currently, it is in a slump, and I feel it needs something more.
Any suggestions/changes that I should make? I really need your help! Thanks!

Charizard @ Charizardite X
Ability: Blaze
EVs: 252 Atk / 252 Spd
Jolly Nature
- Dragon Dance
- Dragon Claw
- Flare Blitz
- Earthquake

Clefable @ Leftovers
Ability: Unaware
EVs: 252 SAtk / 252 Def / 4 HP
Modest Nature
- Cosmic Power
- Stored Power
- Moonlight
- Moonblast

Breloom @ Choice Band
Ability: Technician
EVs: 252 Spd / 252 Atk
Adamant Nature
- Mach Punch
- Bullet Seed
- Rock Tomb
- Force Palm

Azumarill @ Choice Band
Ability: Huge Power
EVs: 252 HP / 252 Atk
Adamant Nature
- Waterfall
- Play Rough
- Aqua Jet
- Superpower

Donphan @ Red Card
Ability: Sturdy
EVs: 252 Atk / 252 Def / 4 HP
Adamant Nature
- Stealth Rock
- Rapid Spin
- Earthquake
- Ice Shard

Garchomp @ Choice Scarf
Ability: Rough Skin
EVs: 252 Spd / 252 Atk
Jolly Nature
- Outrage
- Earthquake
- Stone Edge
- Dragon Claw