Ambipom - lead - normal gem
EVs: 252 speed, 252 attack
Fake out (devastating with STAB+technician, and with that normal gem boost on the first use, look out)
U-turn (clean getaway after a fake out, really gets inside the opponents head when fake out deals a bunch of damage, and then u-turn lets me deal more damage and get away, usually before I even get hit)
Low kick (screws with registeel and rhyperior)
Ambipom's job is too start the battle with a fake out that will help demolish anything that doesn't resist it, in which case u-turn is used, saving my normal gem for when it counts.
Heracross - physical sweeper - toxic orb
EVs: 252 attack, 252 speed
Close combat (STAB, guts boost gives this move insane power)
Facade (guts boost, double power thanks to toxic orb)
Stone edge (coverage)
Heracross uses his ability guts like a glorified life orb, (it's pretty common) using the 50% attack boost to achieve power comparable to a nuclear bomb.
Xatu - Special sweeper - leftovers
EVs: 252 special attack, 252 speed
Ability: magic bounce
Calm mind (stat boosts for sweeping)
Hidden power grass (takes down stealth rock users)
Roost (HP regain for more calm mind spamming)
Remember how ambipom's strategy was to use fake out and then u-turn before the opposition could move? Well xatu is the one that gets switched in, because there is most likely a taunt or hazard or something similar is on the way, and what better to counter that with but magic bounce.
Milotic - Special tank - leftovers
EVs: 252 sp. Defense, 128 HP and sp. attack
Ability: marvel scale
Scald (STAB, annoying burn chance)
Ice beam (coverage)
Recover (HP regain for absorbing more hits)
Dragon tail (switches resisting enemy's and what not while dealing damage)
Milotic is a great special tank, especially with her ability, which just makes her harder to take down when some fool tries to cripple her with status.
Cobalion - physical tank - focus sash
EVs: 252 defense, 252 attack
Iron defense (boosts defense for absorbing physical attacks)
Block (stops the enemy from switching to a special attacker, so I can safely use iron defense)
Sacred sword (STAB)
Iron head (STAB)
Cabalion's job Is to demolish physical attackers by stopping their switching with block, then setting up iron defense and hammering the enemy with STAB moves. Also, if they do get to switch before block is used, then I just switch out to a Pokemon that resists/kills the opponent's.
Dusclops - wall - eviolite
EVs: 252 defense, 252 special defense
Sleep talk (to be used with rest)
Rest (HP regain, Rids him of status)
Shadow punch (STAB)
I have won battles by having the opponent ragequit with this set. Need I say more?