Because ghosts are as powerful as other ghosts in Pokémon.
You can beat a ghost type with another ghost type (Like Haunter)
Dark type can beat ghost.
The Gym Leader is easy to beat. She mainly use's ghost type Pokemon. Ghost Pokemon are weak against Physic Pokemon. Trust me if i can beat her you can.
ghost
Ghost and Psychic
thunder pokemon
I'm afraid there are no types of pokemon that can beat the Ghost type :P
Dark types beat ghost Pokemon, as do those of a higher level with the fire type.
Yes.
Have ALOT of Water and Ghost Pokemon
Using Dark or Ghost type moves against it
Bug, Ghost or Dark.