This is a team I have used in Gen 6 OU on Showdown! a few times.
Altaria @ Altarianite
Ability: Cloud Nine
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Return
- Earthquake
- Roost
- Dragon Dance
Weavile @ Life Orb
Ability: Pressure
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Icicle Crash
- Knock Off
- Pursuit
- Ice Shard
Magnezone @ Choice Specs
Ability: Magnet Pull
EVs: 172 HP / 252 SpA / 84 Spe
Modest Nature
IVs: 0 Atk / 30 SpA / 30 Spe
- Thunderbolt
- Volt Switch
- Flash Cannon
- Hidden Power [Fire]
Gengar @ Black Sludge
Ability: Levitate
EVs: 8 HP / 248 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Hex
- Will-O-Wisp
- Taunt
- Substitute
Celebi @ Leftovers
Ability: Natural Cure
EVs: 252 HP / 152 Def / 104 Spe
Bold Nature
IVs: 0 Atk
- Thunder Wave
- Recover
- Giga Drain
- Healing Wish
Cobalion @ Leftovers
Ability: Justified
EVs: 144 HP / 112 Atk / 252 Spe
Jolly Nature
- Stealth Rock
- Iron Head
- Close Combat
- Volt Switch
Recognise it? You might; I made it from a Smogon article a few months ago when I was less experienced in the competitive scene.
The thing is, my only 'mon that resists fire, a very potent typing, is Altaria, which often doesn't last until all the wall breaking fire-types are out. Talonflame is probably what I see myself losing to the most (despite it losing 1/2 health from Stealth Rock, should I have time to set them up) so a replacement for some of the 'mons that don't do anything very much - namely Celebi and Cobalion (although Celebi has had some of the spotlight in the midgame where the opponent is trying to wall-break recently) - would be highly appreciated. Any other suggestions are welcome too.
Pokémon I would prefer to keep (but changes in their sets are fine):
Altaria
Gengar
Magnezone