Darkrai

Darkrai is a legendary ghost Pokémon that gives people and Pokémon nightmares. Jeffrey, Jaden and their team meet a Darkrai in Jeffrey, Jaden & Friends' Storm Adventures of Pokemon: The Rise of Darkrai. Darkrai was at first thought to be an evil Pokémon after he attacked several people and Pokémon. But it turned out Darkrai was trying to protect Alamos Town from Dialga and Palkia. Darkrai sacrificed himself to save the town and it's people.