Manawyddan fab Llyr is the Yu-Gi-Oh! The Duelists of the Roses incarnation of DarkNite and portrayal of the Welsh mythological figure Manawydan, son of Llyr. He serves as the antagonist of the game and is the only opponent the player will face irrespective of which team they side with, Red or White Roses. He will imply that he is Nitemare's brother when summoned if the player chose to follow the Yorkists, by saying "First you humans awakened my brother from the sands of Egypt and sealed him away again!"