North and South Chapter 7: The Source
dark types must have some sort of immunity because of the inherent nature of a dark type.
Sinori's Tale - Chapter Four
"dark types can feel emotions the same way psychic types can read thoughts.
Chapter Fourteen - One Less Problem
"he's a dark type i can't do a thing!"
Righting Your Wrongs (Chapter 6)
I can only assume that because dark types are the direct opposite to psychics that you already held such an ability.
The Human Species Ch.18 - Pure Legendary Celebi
"sounds like a pretty reckless technique" the gallade said before exhaling in relief over not being forced to fight a dark-type. "dangerous situations call for dangerous techniques" pikablu said confidently while crossing his arms, "hmpf...
Monster I Have Become: Prologue
"hey wait, isn't there a dark-type one." i asked him. "ah! um...yes. there is. it is the dark-type called umbreon." he answered me, surprised i would ask such a question. "but that is not the best choice.
Ember Tails side story - Firedog the First, pt3
Kyle simply gave a go-get-em huff and ran forward to take the first dark-type on, watching as his claws seemed to glow purple a little bit as he charged as well.
Sabetha, The Walker of Fate - Chapter 8, The Mirror of Shattered Dreams
It cackled knowing dark types were immune to psychic types. tremi smirked. "your arrogance is why you lose!"
Lumeria's biography
Skills: - immune to ground types and very resistant in dark types. - she controls everything easily with her powers.
Challenge the Warmachine Chapter 8: Reckless
"but we've seen other pokémon use dark-type moves here even when they weren't dark-types themselves; why does it have such a strong effect on you?" "moves like night slash or punishment don't require aura energy to empower them." luke explained.
Absol's Wish: Epilogue
-yawn-"look abby, as much as i enjoy being led away into the night forest by a dark type... well, is this important?" sandslash turned around and started to walk back. "growlithe and i made out!"
The Human Species Ch. 31 - Somber Psychic Espeon and Cheerful Fighter Umbreon
Lucario took his chance to kick the dark-type's face, but his leg was stopped by the same barrier from before.