He is the son of King Raregroove in the Rave Master franchise.
Lucia Raregroove is once presumed dead in King's flashback during the Tower of Din Arc. Yet, he is alive (It is unknown if King ever knew). According to Gale Glory, Lucia should be the same age as Haru Glory. Lucia gain the knowledge and evil from Mother Sinclair.
Lucia Raregroove, who is created by Hiro Mashima, has no current information on what inspires the author to create him. He first appears in Rave Master episode 44. His Japanese voice actor is Souichiro Hoshi, and his English voice actor is Armando Valdes-Kennedy.
In King's flashback, he is a small boy who was presumed dead with his mother during the Raregroove massacre.