Nitemare Ootsuki

Blue Oni Ootsuki (ブルー鬼大月 Burū oni Ōtsuki) or Nitemare Ootsuki (ナイトまれ 大月 Naitomare Ōtsuki) is a Mercenary with the ability to transform into an Oni, a power he gained after eating the Oni-Oni no Mi (Ogre-Ogre Fruit).