Let's see:

Win Streak 83: proof http://xs.to/media/69112

My team:

Slaking @ Choice Band
Adamant
Truant
6hp/252 atk/252 speed
Giga Impact
Earthquake
Shadow Claw
Fire Punch

Giga impact for STAB (It always K.O 1-2 Foe's pokemon, if not, in the other turn that he attack, he finish his job). Earthquake for Fires, Rocks and Steels.
Shadow Claw for ghost types.

Volcarona @ life orb
Modest
Flame body
2hp/ 252 S.Atk/ 252 Speed
Quiver Dance
Bug Buzz
Fiery Dance
Hidden power rock

My special sweeper. Quiver dance to boost his Sp. Atack and Speed so he can hit harder and faster. Bug Buzz and Fiery Dance for STAB. this thing hits really hard if the foe's pokemon it's not resistant agains it.

Serperior @ leftovers
Timid
Contrary
4 hp/252 sp. attack/ 252 speed
Leaf Storm
Hidden Power Rock
Dragon Tail
Glare

I wanted to test a contrary serperior, so I hacked one (as you can see, with legal ev training and all), And I Love it. He was my "finisher"....I always send him after a oponent KO one of my Pokemon and his hp was low, so I finished it with a leaf storm and gained a +2 sp. attack boost. and then wreak havoc with him. Hidden power rock save me a lot against flyers, some dragons (Dragonite and Salamence), and fire types. I Used dragon tail for force a switch out against a rival that it can't kill yet.

How I Lost: Against a Garchomp....I started with my Slaking, Use Giga Impact, Garchomp Avoid it, it uses swords dance....Slaking needs to recharge, Garchomp uses Dragon Claw...Slaking faints...I send out my volcarona. Garchomp uses swords dance, Volcarona uses Quiver dance...Volcarona uses Hidden power Rock...Garchomp Avoid it -.- .....garchomp uses earthquake...volcarona faints....I send out my Serperior...It uses leaf storm...garchomp uses fire fang, serperior faints.