Use Dark type pokemon.
You must defeat them.
psychic, dark, flying, ghost
Lopuny is a normal type.Use rock,ghost,or steel Pokemon to defeat the Pokemon.
Ghost types are weak against other ghost types and dark types so use those types to defeat that elite four member.
To defeat ghost Pokemon use ghost or dark type moves. If youre fighting a ghost poison you can also use psychic type. normal and fighting types don't affect them but everything else will do normal damage to them
you need to find the silph scope this will reveal the ghost to be a marowak you can then defeat it
psycic Pokemon are weak against ghost type moves bug type moves and dark type moves, you can use ghost, dark and bug moves to deal quite alot of damage
use dark and psychic. normal moves do 0 damage
Alakazam is a tough Pokemon ghost Pokemon can easily defeat it or dark Pokemon like Gengar or Umbreon or Murkrow. Bug Pokemon are also effective against it, but the same works in reverse.
first you need to go to celadon city game corner, activate the poster on the wall. and defeat the team rocket boss. from this you will gain a silph scope this enables you to see the ghost, and defeat it
You have to defeat Giovanni in his secret base at the Celedon game corner, get the silph scope, and then defeat the ghost of Marowak and Team Rocket in the ghost tower in Lavender.
You need the Silph Scope to find the ghost's identity bet you have to get it from Team Rocket's boss. When you defeat him, he will leave it behind. Get it and go to Pokemon Tower. Then go to the stairs where a ghost won't let you pass. You find out the ghost's identity, which is Marowak. Then defeat it and it will calm down and depart to the afterlife.