Is this team balanced?

Yanmega (M) @ Choice Specs Trait: Tinted Lens
EVs: 252 SAtk / 4 SDef / 252 Spd
Timid Nature (+Spd, -Atk)
- Air Slash
- Bug Buzz
- Hidden Power [Ground]
- U-turn
Sceptile (M) @ Grass Gem
Trait: Unburden
EVs: 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Leaf Blade
- Swords Dance
- Acrobatics
- Earthquake
Slaking (M) @ Choice Band
Trait: Truant
EVs: 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Return
- Reversal
- Earthquake
- Hammer Arm
Haxorus (M) @ Life Orb
Trait: Rivalry
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Dual Chop
- Brick Break
- Attract
- Dragon Dance
Cofagrigus (M) @ Leftovers
Trait: Mummy
EVs: 172 HP / 84 Def / 252 SDef
Calm Nature (+SDef, -Atk)
- Night Shade
- Will-O-Wisp
- Toxic
- Protect
Alakazam (M) @ Focus Sash
Trait: Magic Guard
EVs: 4 Def / 252 SAtk / 252 Spd
Modest Nature (+SAtk, -Atk)
- Psychic
- Focus Blast
- Energy Ball
- Hidden Power [Fire]


Edit: Oops, I posted this in the wrong section. Can someone move this to Competitive Battling please?