He is the former Demon Card member and Oracion Seis. After Haru defeats him, he becomes his ally during the Stellar Memories Arc.
Shuda is Gale Glory's friend until Gale defected from Demon Card. He is a cruel man who will insult others and use them. Once he is changed by Haru Glory, he becomes Haru's ally during the Stellar Memories arc. Interestingly, during the Stellar Memories arc, his memories reveal that he and Cattleya share more than information on Gale Glory's death. He tells Haru that he is his brother-in-law after some implied sex scenes of Cattleya.
Shuda, who is created by Hiro Mashima, has no current information on what inspires the author to create him. He appears in Rave Master: Episode # 1 and Rave Master: Volume # 1 of Rave Master. He is one of the first villains we see in the series, and continues to be a bother to Haru and his friends. In the original Japanese anime he is voiced by Toshihiko Seki, and in the English adaption he is voiced by Crispin Freeman.
When Shuda is a member of Oracion Seis, he is a cruel man until he faces Haru. During the Shuda arc, Haru defeats Shuda, and when Shuda is hanging on the ledge of his ship, Haru tries to help him. Shuda who is amazed by Haru's compassion decides to cut his wrist off, so he will not be a burden to Haru. (See anime differences below)
In Hip Hop City, Shuda makes his first appearance after Haru has defeated a Demon Card soldier who uses smoke as his Dark Bring. He has the defeated man whisk away for punishment. During Hole's attempt to let Haru and the others escape, Shuda has his first fight with Haru. At first, Shuda has Haru on the ropes when he uses his Valsyar Flame on Haru. Somehow, when Elie throws Plue at Shuda, Plue causes a distraction when the billboard falls on Shuda. As Shuda looks at the billboard and dodges it, Haru uses Explosion on Shuda's Dark Bring and destroys it. Before Shuda leaves Haru, he tells Haru that he knows his father. Also, Shuda gains some victory when Haru's Ten Commandments sword breaks.
In the Land of Falling Stars (Dub: Tremelo mountains), Shuda, who learns from his men that Haru is coming, cannot wait for their fight. He hires an assassin, Dr. Schneider, to take care of them. After Haru defeat Schneider and obtains the Rave of Knowledge, Shuda appears behind Haru. He attacks Haru with his sword; he uses his Dark Bring's, Barrete Blaze, explosion on him which sends Haru into the Symphonia grave. When Shuda sees the grave, he vandalizes it by blowing up everything completely. After the vandalism, he raises his ship, Rhapsodia, from the caves. The ship rises and lifts Shuda, his henchmen, Haru, and Haru's group into the sky. Shuda continues his fight with Haru; he dodges Haru's Explosion (first) and then Silaphalion. He decides to honor Haru by making the fight more challenging and interesting. He raises the platform, Vanish Field, up to the sky where it becomes an invisible floor. During the fight, Shuda stuns Haru with facts that he and Gale glory are friends in Demon Card. Once Haru is stunned, Shuda kicks him in the gut. When Haru is grabbing the ledge of the Vanish Field, Shuda decides to give Haru demonstrations on how accurate and far his Dark Bring's attacks can go. He creates an explosion on Elie and then Musica. Suddenly, Haru attacks Shuda in rage, but Shuda gives Haru, a powerful explosion. (At some point in the battle, Shuda uses explosion on Haru while Plue tries to protect Haru. Plue's body gets shot at Shuda due to the explosion) Shuda fights Haru who gains his second wind from his flashbacks. Shuda damages his body with his explosion when Haru gets close to Shuda and thinks he has Shuda trapped. Yet, Shuda uses another explosion on Haru, but Haru, who times his attack, dashes at Shuda with Silaphalion because the explosion shoots Haru like a rocket. Shuda meets his defeat when Haru delivers an Explosion on him that breaks his sword. The explosion from Haru's attack sends Shuda over the Vanish Field. Yet, Shuda gets save by Haru. Despite Haru's generosity, Shuda cuts his wrist off (breaks Dark Bring) and tells Haru to believe in himself. (See anime/manga differences below)
Shuda watches Haru's fight with the demons and Gale's fight with King. He speaks to himself that Haru will learn the truth; history will be change when Gale and Haru meet each other. Once Musica and the gang arrive, demons try to attack them. Shuda kills them and tells Elie and her gang to quickly head inside the tower to assist Haru Glory.
Shuda is one of the most powerful characters in the Rave Master world, this is first shown obviously when we see he isn't some low-level "junkie" of Demon Card, but someone of much more importance and higher status. Because of this, we can assume greatly he is very powerful, but we don't actually get to see that until he battles directly against Haru himself.
Unlike the manga, Shuda does not cut his hand off, but he uses his dark bring to blow his hand off. The reasons are to avoid graphic violence for a younger audience.