Dark type Pokémon are weak against fighting and bug type moves.
psychic type pokemon are weak against psychic steel and dark
Spiritomb is Dark/Ghost and has no type weaknesses.
Weak: Psychic Strong: Fighting
The fighting type is weak against Ghost and Dark Pokemon, so a Sableye would be good.
Dark type Pokémon are weak against fighting and bug type moves.
Ghost-type Pokemon are weak against Ghost and Dark-type moves.
Dark-type moves
Dark types are vulnerable to Bug and Fighting types (x2). They resist Dark,Ghost, and physcic type moves (x1/2).
psychic type pokemon are weak against psychic steel and dark
usally fighting and bug (depends if it has a second type)
Spiritomb is Dark/Ghost and has no type weaknesses.
light type does not exist, but if such Type were real it's highly likely that Light would be strong against Dark and Ghost and weak against Dark.
Weak: Psychic Strong: Fighting
If I understand your question correctly, Dark, Psychic, and Grass are weak against Bug.
The fighting type is weak against Ghost and Dark Pokemon, so a Sableye would be good.
I know it's weak to Dark type, and I think it's weak to Ghost type but I'm not sure.