Dark-Types are weak against Bug-Types and Fighting-Types.
Dark-Type Pokemon are weak against: Fighting-Types Bug-Types
Dark, and ghost.
Weak: Psychic Strong: Fighting
Psychic-Type moves are weak against Steel-Types and other Psychic-Types. Psychic-Type Pokémon are weak against Ghost-Types, Bug-Types, and Dark-Types.
Ghost types are fundamentally weak against ghost or dark attacks.
Dark-Types are weak against Bug-Types and Fighting-Types.
Dark-Type Pokemon are weak against: Fighting-Types Bug-Types
Dark, and ghost.
Natu is a Psychic and Flying type Pokemon it is weak against Electric types, Rock types, Ghost types and Dark types.
The pokemon that are strong against psychic are bug, dark, and ghost.
Psychic is strong against Poison and Fighting, weak against Psychic and Steel, and has no effect on Dark. Bug, Dark, and Ghost are strong against Psychic. Psychic and Fighting are weak against it. There are no types that have zero effect on it.
Weak: Psychic Strong: Fighting
Psychic-Type moves are weak against Steel-Types and other Psychic-Types. Psychic-Type Pokémon are weak against Ghost-Types, Bug-Types, and Dark-Types.
When attacking, Ghost-Type Pokémon are strong against Psychic-Types and other Ghost-Types, weak against Dark-Types and Steel-Types, and useless against Normal-Types. When being attacked, Ghost-Type Pokémon are strong against Bug-Types and Poison-Types, weak against Dark-Types and other Ghost-Types, and invincible against Normal-Types and Fighting-Types (barring the use of a move like Foresight).
No. Fire-Types are strong against Grass-Types, Bug-Types, Ice-Types, and Steel-Types. Dark-Types are weak against Bug-Types and Fighting-Types.
Ghost types are weak against Dark and Ghost type moves.