Dark-type Pokémon are now immune to opposing Pokémon's moves that gain priority due to Prankster, including moves called by moves that call other moves (such as Assist and Nature Power) and excluding moves that are repeated as a result of Prankster-affected Instruct or moves that occur earlier than their usual order ...

Does prankster work with rain dance?

In the VGC 2020 metagame thus far, both Sun and Rain teams often made use of a Prankster Pokemon setting manual rain for its partner to take advantage of. Sableye gets both Sunny Day and Rain Dance, and Whimsicott gets Sunny Day. Both can support teams outside of the weather moves.

What is Dark type weak to?

Dark-type Pokémon have resistances to Ghost, other Dark, and Psychic-type Pokémon. But they are vulnerable to Fighting, Bug, and Fairy-type moves.