Gardevoir
Attachment: Lum Berry
Personality: Calm
Trait: Synchronize
Moves: Psychic/HP [Dark]/Will-O-Wisp/Calm Mind
Ev's:146/0/0/252/0/112
Walrein
Attachment: Leftovers
Personality: Modest
Trait: Thick Fat
Moves: Ice Beam/HP [Electric]/Surf/Rest
EV's:252/0/126/0/0/130
Hariyama
Attachment: Leftovers
Personality: Adamant
Trait: Thick Fat
Moves: Cross Chop/Frustration/Bulk Up/Rest
EV's: 6/0/252/0/0/252
Claydol
Attachment: Leftovers
Personality: Impish
Trait: Levitate
Moves: Earthquake/Reflect/Light Screen/Explosion
EV's: 252/0/130/0/0/128
Dusclops
Attachment: Leftovers
Personality: Calm
Trait: Pressure
Moves: Ice Beam/Calm Mind/Will-O-Wisp/Rest
EVs:252/0/108/0/42/108
Skarmory
Attachment: Leftovers
Personality: Impish
Trait: Sturdy
Moves: Drill Peck/Roar/Toxic/Spikes
EV's:252/52/136/6/0/64
I like the way you've done this team and having HP Electric on Walrein is a good idea for beating those Gyarados that try to take out your whole team. I haven't changed much stuff because this team is pretty good to begin with.
~Andrew