Darkrai, also known as the Pitch-Black Pokémon, is a Dark-type Mythical Pokémon originating from Generation IV, and a member of the Lunar Duo alongside Cresselia. Although in the anime, Darkrai is seen as a hero. In some video games, he is an antagonist who is bent on ruling the whole world of Pokémon and making it a world of darkness. His most important role as a villain is in Pokémon Mystery Dungeon 2: Explorers of Time, Darkness, and Sky, where he is the true main antagonist of the game and he is also the main antagonist of Pokémon Mystery Dungeon: Explorers of Time, Explorers of Darkness, and Explorers of Sky. Though he mainly appears in the post-game plot, he is revealed to have orchestrated the events of the entire game.
In the first half of the post-game plot, Darkrai posed underneath the pseudonym of "Cresselia", adapted her personality and took her appearance, using it to pursue the protagonist and their partner.
In Villains Battles he joined Scar to be his protector and help him with his plans.