Ghost & Flying. I believe that's it! Not dark or bug because although they're super-effective against Psychic, they are not-effective against Fighting. And not Psychic, because though it's super-effective against Fighting, it's not-effective against Psychic.
Water and Grass attacks are super effective against Onix.
psychic pokemons and attacks are super effective
super effective is bug
Rock, electric, ice, and psychic types are super effective against Crobat.
Have a diverse team, make sure there isn't a type that is super effective against all your pokes. -Blastoise -Gengar --Alakazam -Pidgeot -HM Pokemon X2 -Blastoise is super effective against rock, ground and fire -Gengar is super effective against ghost,grass and bug -Alakazam is super effective against fighting and poison -Pidgeot is super effective against bug fighting grass
Flying and Psychic are super effective against fighting
Lightning is super effective against Water and Flying types in Pokémon battles.
Ghost & Flying. I believe that's it! Not dark or bug because although they're super-effective against Psychic, they are not-effective against Fighting. And not Psychic, because though it's super-effective against Fighting, it's not-effective against Psychic.
Water and Grass attacks are super effective against Onix.
psychic pokemons and attacks are super effective
super effective is bug
Bug Type and Fighting Type moves are super effective against it.
Rock, electric, ice, and psychic types are super effective against Crobat.
Steel is super effective against rock type pokemon.
Machamp is a fighting type Pokemon all fighting Pokemon are weak against flying types and psychic types that use flying type and psychic type moves so Pokemon like pidgeot or alakazam will do good against machamp.
normal type Pokemon are not super effective against any type.