electric, ice, rock
Dark Pokemon, with the exception of a few, including, but not restricted to Spiritomb, Sableye, Drapion, and Honchcrow, are all weak against Bug- Type and Fighting-Type moves.
All of his Pokemon are weak against weak rock type moves, which I would use against Honchcrow, a Steelix that knows a rock move against Weavile and Crowbat, and a Rotom, Pachirisu, or Luxray against Gyarados. They should probabally all be past Lv. 47. He uses type advantages, so if you use a Psycic type on Crowbat, he will send out Weavile or Honchcrow, who are not affected by Psycic type moves.
The best type of Pokemon against electric types are ground type Pokemon Hope it helped!
Fighting type Pokemon
Ghost or dark pokemon
Some of his Pokemon include: Honchcrow, Crobat, Gyrados, and a few others. so what i suggest is use an Electric type you can take out Gyrados Crobat and Honchcrow easily he also has a weavle so use a fire type agaisnt tht and after that the rest of your team is up to you
The best type of Pokemon against electric types are ground type Pokemon Hope it helped!
Normal type pokemon are best and rock type pokemon also.Electric attacks against rock type pokemon become ineffective.
ghost or dark types
A water type would be best.
Fire Extinguisher
There are 3 types that work best against psychic Pokemon: Bug,Rock,Ghost, and Dark.