OU Mix-Tier (mostly for in-game)

[Proteun]

This is my first serious team! Have been battling with it for some time now and it's doing great - but not perfect of course :)

♦ Heracross♂ @Choice Scarf
Adamant, 252 Atk/252 Spe/4 HP
Ability: Moxie
• Close Combat
• Megahorn
• Earthquake
• Stone Edge

♦ Blastoise♀ @Blastoisinite
Modest, 252 SpA/252 HP/4 SpD
Ability: Torrent
• Rapid Spin
• Dark Pulse
• Aura Sphere
• Water Pulse

♦ Garchomp♀ @Life Orb
(Not EV trained nor bred, it's doing great already - would probably be 252 Atk/252 Spe/4 HP)
Ability: Sand Veil
• Swords Dance
• Earthquake
• Crunch
• Dragon Claw

♦ Zoroark♂ @Focus Sash
Modest, 252 Spe/252 SpA/4 HP
Ability: Truant Illusion
• Flamethrower
• Focus Blast
• Extrasensory
• Dark Pulse

♦ Florges♀ @Leftovers
Calm, 252 SpD/128 SpA/128 HP (Wanted some offensive Fairy-power as well, and its HP wasn't that good)
Ability: Flower Veil
• Calm Mind
• Protect
• Moonblast
• Wish

♦ Ferrothorn♀ @Rocky Helmet
Impish, 252 HP/252 Def/4 SpD
Ability: Iron Barbs
• Gyro Ball
• Curse
• Stealth Rock
• Leech Seed

I should probably actually breed for a Garchomp. Heracross is mostly used as Illusion food, since Psychic can be used on it an no-one will ever use Fighting or Bug. I switch frequently between Ferrothorn and Florges depending on the opponent's attack. Ferrothorn can often take out physical attackers because of his recoil. I don't use Stealth Rock that often, by the way. Maybe I could replace it for a Leech Seed/Protect set.

 

[PlatinumDude]

There's no such thing as a mix-tiered team because the highest-tiered Pokemon on that team will make that team playable in that tier only.

Heracross' Mega Evolution is the sole reason why Heracross itself is even used in the first place because of the raw power it provides:
-Pin Missile/Substitute
-Close Combat
-Rock Blast
-Swords Dance/Substitute
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Heracronite
Ability: Guts/Moxie

Now that the Mega slot is taken up by someone else, Blastoise will have to be replaced. It's alright in OU, but Starmie can also perform a bulky Rapid Spin set because of its access to Recover and the ability to use Reflect Type to prevent itself from being bait to Bisharp and Ferrothorn:
-Scald
-Rapid Spin
-Reflect Type
-Recover
Nature: Timid
EVs: 248 HP/20 Def/16 SDef/224 Spe
Item: Leftovers
Ability: Natural Cure

There's little reason for Garchomp to use Crunch because it doesn't provide noteworthy coverage; a 2x super effective Crunch barely outdamages a neutral STAB Earthquake. Fire Fang (for Ferrothorn, Skarmory and Scizor) or Stone Edge (for Togekiss) are better alternatives.

Zoroark is rather subpar because it can't do much to Fairies. Better Dark Pokemon to turn to are Bisharp, Greninja or Tyranitar. The former needs Poke Transfer for Knock Off, one of its best moves. If you can't do that, wait until Omega Ruby/Alpha Sapphire because Knock Off became a move tutor again in those games:

Bisharp:
-Sucker Punch
-Iron Head
-Knock Off
-Pursuit/Swords Dance
Nature: Adamant
EVs: 4 HP/252 Atk/252 Spe
Item: Black Glasses/Dread Plate/Life Orb
Ability: Defiant

Greninja:
-Hydro Pump
-Ice Beam
-Grass Knot/Hidden Power (Grass)/Extrasensory/Spikes
-Dark Pulse/Hidden Power (Fire)/Extrasensory/Spikes
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb
Ability: Protean

Tyranitar:
-Stone Edge
-Crunch/Ice Punch
-Pursuit
-Superpower/Earthquake/Fire Blast
Nature: Jolly/Naive
EVs: 252 Atk/4 Def/252 Spe
Item: Choice Scarf
Ability: Sand Stream

Really, what does Florges do that Sylveon and Clefable can't? For one thing, its abilities are useless and for another, it has roughly the special same bulk as Sylveon, which has better offensive presence in Pixilated Hyper Voices. Clefable's wider move pool also gives it an edge over Florges. Heck, even Togekiss is more useful because of similar reasons to Clefable:
252 SpA Life Orb Greninja Hydro Pump vs. 252 HP / 252+ SpD Florges: 107-126 (29.7 - 35%) -- guaranteed 4HKO after Leftovers recovery

252 SpA Life Orb Greninja Hydro Pump vs. 252 HP / 252+ SpD Sylveon: 121-142 (30.7 - 36%) -- guaranteed 4HKO after Leftovers recovery

Sylveon:
-Wish
-Protect
-Hyper Voice
-Heal Bell
Nature: Bold
EVs: 252 HP/220 Def/36 SDef
Item: Leftovers
Ability: Pixilate

Clefable:
-Calm Mind
-Moonblast
-Stored Power/Flamethrower
-Soft-Boiled/Moonlight
Nature: Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers/Life Orb
Ability: Magic Guard

or
-Wish
-Protect
-Moonblast
-Heal Bell/Aromatherapy/Thunder Wave
Nature: Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Unaware

or
-Moonblast
-Fire Blast
-Thunder Wave
-Soft-Boiled/Moonlight
Nature: Modest
EVs: 252 HP/4 Def/252 SAtk
Item: Life Orb
Ability: Magic Guard

or
-Stealth Rock
-Moonblast
-Fire Blast
-Soft-Boiled/Moonlight
Nature: Calm
EVs: 252 HP/160 Def/96 SDef
Item: Leftovers
Ability: Magic Guard

Togekiss:
-Thunder Wave
-Air Slash
-Heal Bell/Defog/Dazzling Gleam/Aura Sphere/Flamethrower
-Roost
Nature: Bold/Calm
EVs: 248 HP/252 Def/8 SDef (Bold) or 248 HP/8 Def/252 SDef (Calm)
Item: Leftovers
Ability: Serene Grace

or
-Nasty Plot
-Air Slash
-Aura Sphere/Heal Bell
-Roost
Nature: Modest
EVs: 4 Def/252 SAtk/252 Spe
Item: Leftovers/Lum Berry
Ability: Serene Grace

or
-Nasty Plot
-Air Slash
-Roost
-Baton Pass
Nature: Calm
EVs: 248 HP/244 SDef/16 Spe
Item: Leftovers
Ability: Serene Grace

Really, Ferrothorn is doing too much at once. Curse sets need too much support to function, such as removing Ferrothorn's weaknesses. It also makes Ferrothorn more susceptible to Taunt. Here's a better set for it:
-Stealth Rock
-Leech Seed
-Power Whip
-Gyro Ball/Protect/Knock Off
Nature: Relaxed
EVs: 252 HP/88 Def/168 SDef
Item: Leftovers
Ability: Iron Barbs

or
-Spikes
-Leech Seed
-Protect/Power Whip/Gyro Ball
-Gyro Ball/Thunder Wave
Nature: Relaxed
EVs: 252 HP/88 Def/168 SDef
Item: Leftovers/Shed Shell
Ability: Iron Barbs

 

[Polar Spectrum]

Looks pretty decent to me cornflakes, I've never used heracross for zoroarks illusion before- that's a good one. I'd love to play against this team sometime if you have the time / chance to ^^