Quote from Shrukan
I am training up my Misdreavus, and I am going to train it.
...?
Well... Let's see...
The first guy has bug-type Poke's. The first one he sends out is Dustox (Bug/Poison). Psychic, Flying, Fire would do the trick on that sucker.
He also has Vespiquen(sp.) -- a Bug-Flying which REALLY hates Rock -- as well as Beautifly (also REALLY hates Rock), Heracross (REALLY hates Flying), and Drapion (hates Ground). Drapion and Vespiquen are his "strongest", in my opinion.
Next, you'll face a Ground-related person. Ice types, Water types and Grass types would do pretty well here. Quagsire is the first Pokemon sent out (a Ground/Water type, only hates Grass). Head honcho: Hippowdon (pure Ground type).
Thirdly, a fire dude. He'll send out Rapidash first. Water would to really well here. I would say Infernape is the lead one here for this guy...
Fourthly, a Psychic dude (oh, boy, did I have troubles with him my first time around). He'll send out Mr. Mime first (pure Psychic, pretty poor defense). Head honcho here: Bronzong. Oy, do I HATE this one. A Steel/Psychic, therefore it hates Ground and Fire... but it has Levitate, so it only hates Fire. It knows Calm Mind, Gyro Ball, and Psychic (I think?), I cannot remember that last move... It's also holding a Sitrus Berry, if I recall correctly. Make sure you have someone good enough to hit both the Defense and Sp. Defense of this guy. Whoo...
And, finally, the Championess: Her first Pokemon will be Spiritomb (Ghost/Dark type, no weaknesses therefore). If it uses "Embargo", you won't be able to use healing items (such as Berries or Potions) on Embargo'd Pokemon unless you switch out, so HEAL BEFORE BATTLING HER.
Her two head Pokemon: Lucario (Steel/Fighting type, but REALLY bad defenses), and Garchomp (HATES Ice bigtime). Others include Milotic (DO NOT USE SPECIAL ATTACKS ON MILOTIC UNLESS YOU ARE SURE THEY WILL TAKE IT OUT! It knows Mirror Coat, so if you were to use Spacial Rend and get a Critical Hit but it survives, it will Mirror Coat your Spacial Rend at DOUBLE POWER. Yep. Pretty annoying...), Roserade (not much of a threat, in my opinion), and Gastrodon (Water/Ground type, only hates Grass of course, but can be annoying).
Yeah... I'm thinking your team may need a Flying-type, but that could be just me.