Heyo, I'm Dragonpolabear, and here's my attempt at entering the OU competitive scene.
Now, without any more delay, let's start, shall we?
With this team, I run a lot of revenge killers (5 to be exact) to basically surprise the enemy.
I playtest on the Pokemon Online main server, under the name Dragonpolabear. If you want, pop in and we can duel or something.
Forretress
Item: Leftovers
Ability: Sturdy
Nature: Relaxed
EV's: 252 HP, 252 Def. 4 Spd
Rapid Spin
Volt Switch
Stealth Rock
Gyro Ball
With this set, I send Forretress in as a suicide rocks user. Normally what happens is:
T1: Stealth Rock
T2: Either gets OHKO'D, Rapid spins in case of spikes/rocks, Volt Switches, or Gyro balls
T3-onward: Rinse and Repeat.
Tyranitar
Item: Choice Band
Ability: Sand Stream
Nature: Hasty
EV's: 252 Atk, 240 Spd, 16 HP
SuperPower
Pursuit
Crunch
Stone Edge
What I do with TTar is to kill whatever was out first, and set up a Sandstorm for my next Pokemon. With a huge amount of Attack, an Expert Belt, and a wide array of Moves, TTar can kill a lot of things.
Aron
Item: Shell Bell
Ability: Sturdy
Nature:Timid
EV's:252 SAtk, 252 Spd, 4 Def
Endeavor
Protect
Toxic
Hidden Power (Ground)
Say hello to my main sweeper. With Aron, I can bring opponents down to 1-12 HP, then I kill them with my Sandstorm. If for some reason my Sandstorm isn't up,or my opponent is immune to Sandstorm, then my Shell Bell will heal me back to full, then I can use Hidden Power or Toxic to kill them.
Azumarill
Item: Choice Band
Ability: Huge Power
Nature: Adamant
EV's: 252 HP, 252 Atk, 4 Spd
Superpower
Aqua Jet
Double-Edge
Ice Punch
This bro is one of my favorite revenge killers and pokemon in general. With a Priority +1, STAB, Water type move with about double the power (AKA Aqua Jet), I can sweep a lot of things.
Mienshao
Item: Life Orb
Ability: Regenerator
Nature: Naive
EV's: 252 Atk, 24 Satk, 232 Spd
Hi Jump Kick
Stone Edge
Hidden Power (Ice)
U-turn
This sweeper can do a lot of things with this move set. The Satk is meant for the Hidden Power, and I normally can chunk HP with my Hi Jump Kick. The Stone Edge can kill a lot of fliers, and the U-Turn can switch out easily.
Celebi
Item: Leftovers
Ability: Natural Cure
Nature: Calm
EV's: 252 HP, 236 Sdef, 20 Spd
Psychic
Recover
Thunder Wave
Heal Bell
Celebi is another one of my leads for this team. As a Special Tank, I can set up some heal bells, T-wave my opponents, recover necessary health, and blast the HP out of them with my Psychic.
Now, without any more delay, let's start, shall we?
With this team, I run a lot of revenge killers (5 to be exact) to basically surprise the enemy.
I playtest on the Pokemon Online main server, under the name Dragonpolabear. If you want, pop in and we can duel or something.

Forretress
Item: Leftovers
Ability: Sturdy
Nature: Relaxed
EV's: 252 HP, 252 Def. 4 Spd
Rapid Spin
Volt Switch
Stealth Rock
Gyro Ball
With this set, I send Forretress in as a suicide rocks user. Normally what happens is:
T1: Stealth Rock
T2: Either gets OHKO'D, Rapid spins in case of spikes/rocks, Volt Switches, or Gyro balls
T3-onward: Rinse and Repeat.

Tyranitar
Item: Choice Band
Ability: Sand Stream
Nature: Hasty
EV's: 252 Atk, 240 Spd, 16 HP
SuperPower
Pursuit
Crunch
Stone Edge
What I do with TTar is to kill whatever was out first, and set up a Sandstorm for my next Pokemon. With a huge amount of Attack, an Expert Belt, and a wide array of Moves, TTar can kill a lot of things.

Aron
Item: Shell Bell
Ability: Sturdy
Nature:Timid
EV's:252 SAtk, 252 Spd, 4 Def
Endeavor
Protect
Toxic
Hidden Power (Ground)
Say hello to my main sweeper. With Aron, I can bring opponents down to 1-12 HP, then I kill them with my Sandstorm. If for some reason my Sandstorm isn't up,or my opponent is immune to Sandstorm, then my Shell Bell will heal me back to full, then I can use Hidden Power or Toxic to kill them.

Azumarill
Item: Choice Band
Ability: Huge Power
Nature: Adamant
EV's: 252 HP, 252 Atk, 4 Spd
Superpower
Aqua Jet
Double-Edge
Ice Punch
This bro is one of my favorite revenge killers and pokemon in general. With a Priority +1, STAB, Water type move with about double the power (AKA Aqua Jet), I can sweep a lot of things.

Mienshao
Item: Life Orb
Ability: Regenerator
Nature: Naive
EV's: 252 Atk, 24 Satk, 232 Spd
Hi Jump Kick
Stone Edge
Hidden Power (Ice)
U-turn
This sweeper can do a lot of things with this move set. The Satk is meant for the Hidden Power, and I normally can chunk HP with my Hi Jump Kick. The Stone Edge can kill a lot of fliers, and the U-Turn can switch out easily.

Celebi
Item: Leftovers
Ability: Natural Cure
Nature: Calm
EV's: 252 HP, 236 Sdef, 20 Spd
Psychic
Recover
Thunder Wave
Heal Bell
Celebi is another one of my leads for this team. As a Special Tank, I can set up some heal bells, T-wave my opponents, recover necessary health, and blast the HP out of them with my Psychic.