Ryū Rasen (螺旋 龍) appears in "Ninku Knife no Bohyō" as the leader of a pirate crew and a former Ninku organization member. His primary ability allows him to control fire, stemming from his Ninku martial arts background. During the narrative, he and his crew invade Makoto's village, abducting villagers to enslave them. These captives are forced to construct a pirate fortress on a prison island.