Lucciola is Dio Eraclea's loyal friend/bodyguard. He is an exceptional martial artist. He was assigned the role of protecting him from a very early age, and Dio considers Lucciola not just a servant, but also a friend.

Spoiler

Lucciola is forced to betray that trust out of fear of Maestro Delphine Eraclea when Maestro ordered him to bring Dio back before her. Lucciola then redeems himself by helping Claus, and Alvis and Dio escape from the grasp of the Maestro. In a confrontation against the Maestro, Lucciola kills his brother, Cicada, and is then disintegrated by a device (a ring) that is given to him by Maestro Delphine as a "gift." Lucciola's name is the Italian word which means firefly.