Cael has seen a mysterious pokémon in the Coronet Highlands and asks you to investigate.

The Request

This request is only available if you have Pokémon Brilliant Diamond or Pokémon Shining Pearl save data on the same user account on your Nintendo Switch that you are playing Pokémon Legends: Arceus with. Check on the blackboard in Professor Laventon's office in Galaxy Hall in Jubilife Village to accept this request. Cael will say he saw the pokémon near Clamberclaw Cliffs in the Coronet Highlands.

Investigate the Clamberclaw Cliffs at Night

Go to the Coronet Highlands and sleep at a base camp until nightfall, then go to the guidance marker for this request. Afterward, Darkrai will appear. Don't throw Poké Balls directly at it, or it will become invisible. Instead, throw partner pokémon near where it appears, to start the battle with it. Then try reducing its HP and inflicting status conditions, then throw Ultra Balls (or whatever types of Poké Balls you have available) until you catch it.

Reward

You will get 1 Exp. Candy XL.