
Crobat @ Wide Lens
Nature: Jolly(+ Spd, - SAtk)
Ability: Inner Focus
Ev's: 124 Hp/132 Atk/252 Spd
Hypnosis
Screech
U-Turn
Aerial Ace
Put their lead to sleep, as it's faster then pretty much anything that isn't scarfed. Screech whatever they switch in, then U-Turn out. Almost always prepares something to be trapped and killed.

Celebi @ Leftovers
Nature: Bold(+ Def, - Atk)
Ability: Natural Cure
Ev's: 252 Hp/216 Def/40 Spd
Recover
Thunder Wave
Stealth Rock
Grass Knot
Set's up rocks, or paralyze the sweeper they likely switch in. Knot is for damage, and Recover makes sure it won't die anytime soon.

Dugtrio @ Choice Band
Nature: Jolly(+ Spd, - SAtk)
Ability: Arena Trap
Ev's: 88 Hp/252 Atk/216 Spd
Earthquake
Aerial Ace
Stone Edge
Sucker Punch
Revenge killer, and a good switch in from Crobat's U-Turn. Helps deal with Blissey and a few other poke's who would be troublesome otherwise.

Magnezone @ Leftovers
Nature: Modest(+ Satk, - Atk)
Ability: Magnet Pull
Ev's: 164 Hp/92 Spd/ 252 SAtk
Substitute
Magnet Rise
Thunderbolt
Hidden Power[Ice]
Skarmory is a common switch in to Crobat, so Magnezone can kill it before it can set up. Deals similarly with Bronzong and Metagross, as long as I'm sure to avoid EQ. With a sub up, this guy can become a huge pain for just about any team.

Gyarados @ Life Orb
Nature: Adamant(+ Atk, - SAtk)
Ability: Intimidate
Ev's: 4 Hp/252 Atk/252 Spd
Dragon Dance
Earthquake
Waterfall
Ice Fang
Comes in late game, and sweeps up from there. Stops Scizor and Heatran cold in there tracks, who would otherwise be a huge threat to the team.

Blissey @ Leftovers
Nature: Calm
Ability: Natural Cure
Ev's: 252 Def/80 SAtk/176 SDef
Wish
Protect
Ice Beam
Seismic Toss
The team has done well so far, though Latias has proven to be a problem. Any advice on how to fix that would be greatly appreciated.