This article contains detailed information regarding the changes for the ability Prankster in Pokémon Sun and Moon.
What is the ability Prankster?
Prankster is an ability that boosts the priority of Status Moves by +1.
It was introduced back in Fifth Generation and Pokemon such as Whimsicott, Thundurus, and Tornadus have this ability.
What are the changes to this ability?
Dark-type Pokemon are now immune to moves boosted by Prankster.
In other words, the priority-boosted Status Moves used by these Pokémon with the ability Prankster can no longer affect Dark-Types.
Keeping in mind of previously mentioned move effect nerfs: Thunder Wave, and Swagger; and status effect nerfs: Paralysis, Confusion, and Burn on which notable Pokémon such as Whimsicott and Thundurus highly depend on to cripple and stall opponents; this can be a challenge for Players who capitalize on using these strategies to secure a victory.