Team for Tournament, 5th Gen only.

[Porygon Z]

Gigalith @ Lum Berry
Nature: Adamant
Trait: Sturdy
EVs: 252 HP/252 Atk/4 Def
- Stealth Rock
- Earthquake
- Rock Blast
- Explosion

The lead. SR, EQ as coverage, RB for some nice STAB damage and breaks subs, Explosion for a 1:1 kill.

Leavanny @ Toxic Orb
Nature: Adamant
Trait: Leaf Guard
EVs: 4 HP/252 Atk/252 Spe
- Camouflage
- Facade
- Razor Leaf
- Shadow Claw

Physical attacker. Camouflage + Facade for obvious combo, it would be a strong 210 base attack move. RL and SC for coverage.

Chandelure @ Choice Scarf
Nature: Modest
Trait: Shadow Tag
EVs: 4 Die/252 SpAtk/252 Spe
- Shadow Ball
- Flamethrower
- Energy Ball
- HP Fighting

Revenge killer of the situation.

Haxorus @ Muscle Band
Nature: Adamant
Trait: Mold Breaker
EVs: 4 HP/252 Atk/252 Spe
- Dragon Dance
- Double Chop
- Brick Break
- Earthquake

Awesome sweeper. DD+DC for huge damage, and breaks subs and Sturdy. Brick Break for Ice types. Earthquake to hit Eelektross and other guys with Levitate.

Ferrothorn @ Shed Shell
Nature: Relaxed
Trait: Iron Barbs
EVs: 248 HP/200 Def/62 SpDef
- Gyro Ball
- Power Whip
- Spikes
- Leech Seed

Staller.

Jellicent @ Leftovers
Nature: Calm
Trait: Water Absorb
EVs: 252 HP/ 4 Def/252 SpDef
- Scald
- Ice Beam
- Pain Split
- Toxic

Special wall.

Not much time to add comment, maybe later.
Rate it, criticism are hugely allowed. :)

 

[OneofFour]

Few things.

Jellicent can get Recover, use that instead of Pain Split, because it has a rather large HP pool.

And why Lum Berry on Gigalith? Off the top of my head, the only common lead running a really threatening status is probably Hypnosis Politoed, or a rare Grasswhistle Whimsicott, who is better off using Surf/Scald (or Giga Drain, in the case of Whimsicott) on Gigalith anyways. Poison and paralysis won't affect you much, since he is already slow, and appears to be something close to a suicide lead. Note, though, that Explosion is not as powerful as it used to be, and you may disappointed when it fails to kill something it hits for even neutral damage.

Also, go ahead and run Life Orb instead of the Muscle Band on Hax, its defenses aren't high enough to be taking many hits anyways, so you may as well take the extra power while you can get it.

 

[Conjurer]

I see Leavanny as dead weight to your team; two mons who has double weaknesses to fire aren't going to form some magical synergy. I recommend switching it out for a more reliable physical attacker with a much better typing, possibly Gliscor (who can still abuse Facade should you choose to do so, due to Poison Heal + Toxic Orb). Try this set:

Gliscor (M) @ Toxic Orb
Trait: Poison Heal
EVs: 252 HP / 184 Def / 72 Spd
Impish Nature (+Def, -SAtk)
- Swords Dance
- Earthquake
- Ice Fang / Facade
- Taunt

 

[OneofFour]

Eh, I disagree with the sentiment that the fire weakness poses a problem, all of his other pokemon resist it, and as long as there remain no pursuit-like fire moves, he can always absorb them through others.

But something I just noticed: Shadow Tag Chandelure is commonly banned.

 

[pokehearts]

I see Leavanny as dead weight to your team; two mons who has double weaknesses to fire aren't going to form some magical synergy. I recommend switching it out for a more reliable physical attacker with a much better typing, possibly Gliscor (who can still abuse Facade should you choose to do so, due to Poison Heal + Toxic Orb). Try this set:

Gliscor (M) @ Toxic Orb
Trait: Poison Heal
EVs: 252 HP / 184 Def / 72 Spd
Impish Nature (+Def, -SAtk)
- Swords Dance
- Earthquake
- Ice Fang / Facade
- Taunt

Uhhhhh, you do know that this isn't a wi-fi team, but a team for the official competition. Which only allows 5th gen pokemon. you did know that. right?

 

[Porygon Z]

But something I just noticed: Shadow Tag Chandelure is commonly banned.

Yeah, I know. Hopefully it wasn't disallowed for this tournament.
The only things that are disallowed are Victini, Reshiram, Zekrom, and the move Sky Drop.

And, what could I use in replace of Leavanny?

 

[TwilightBlade]

I am assuming this is VGC 2011 doubles rules then....
Top threats would be: Hydreigon, Chandelure, Whimsicott, Jellicent, Reuniclus, Conkeldurr, Amoongus, etc. ^^

Gigalith @ Lum Berry
Nature: Adamant
Trait: Sturdy
EVs: 252 HP/252 Atk/4 Def
- Stealth Rock
- Earthquake
- Rock Blast
- Explosion

The lead. SR, EQ as coverage, RB for some nice STAB damage and breaks subs, Explosion for a 1:1 kill.

Leavanny @ Toxic Orb
Nature: Adamant
Trait: Leaf Guard
EVs: 4 HP/252 Atk/252 Spe
- Camouflage
- Facade
- Razor Leaf
- Shadow Claw

Priority Taunt/Encore Whimsicott will damper your chances of setting Rocks and Camouflage. I'd replace Leavanny with Mienshao. Its a fast, reliable physical attacker and has a plethora of options for doubles. Mienshao is a good lead because of Fake Out. Its ability, Inner Focus, prevents others from successfully using Fake Out on it. If you're not worried about opposing Fake Outs, use Regenerator. Rock Slide hits both opponents. Choose whichever fighting move you like (Drain Punch patches up Life Orb recoil). For team support options in doubles, Mienshao can use Wide Guard (for blocking opposing multi-target moves) and Protect (for dodging Earthquake from Gigalith too) and maybe even Taunt (stop weather/trick room) if you're not facing Prankster enemies.

Mienshao @ Life Orb / Fighting Gem
Nature: Jolly
Trait: Inner Focus
EVs: 4 HP / 252 Atk / 252 Spe
- Fake Out
- Rock Slide
- Drain Punch / Hi Jump Kick
- Wide Guard / Protect / Taunt

Chandelure @ Choice Scarf
Nature: Modest
Trait: Shadow Tag
EVs: 4 Die/252 SpAtk/252 Spe
- Shadow Ball
- Flamethrower
- Energy Ball
- HP Fighting

You can't use Shadow Tag Chandelure.. It's Dream World ability is not released yet. Use this set if you don't like Trick Room. Flash Fire is useful for switching into other Chandelure but Flame Body is preferred. Overheat and Shadow Ball are for STAB. Heat Wave is useful in doubles. Remaining moves will reflect your team's weaknesses.

Chandelure @ Choice Scarf
Nature: Modest
Trait: Flame Body
EVs: 4 HP / 252 SpA / 252 Spe
- Overheat
- Shadow Ball
- Heat Wave
- HP Ice / HP Fight / Psychic