BugGhost
Bug and Ghost types: weaknesses, resistances and Pokémon
Bug and Ghost Pokémon take double damage from Fire, Flying, Rock, Ghost and Dark moves, resist Grass, Poison, Ground and Bug moves and are immune to Normal and Fighting moves.
The balance is even: 5 weaknesses and 6 resistances or immunities.
Bug moves are super effective against Grass, Psychic and Dark and not very effective against Fire, Fighting, Poison, Flying, Ghost, Steel and Fairy. Ghost moves are super effective against Psychic and Ghost and not very effective against Dark.
To beat these Pokémon, your best pick is Fire, Flying and Rock moves. Avoid Grass, Poison, Ground and Bug moves, which deal little or no damage.
There is 1 Pokémon with this combination, such as Shedinja.