Vincent Bari (ヴィンセント・バリーVinsento Barī) and the Russian human Gustav (グスタフGusutafu) are an extremely powerful team in the tournament. They utilize Vortex Magic, rotational-based magical attacks. Obsessed with proving his own strength, Bari initially fights one Mamodo opponent after another to defeat them, yet can never get over his own obsession and goes on without purpose or meaning. Hearing about Zatch from another opponent, Bari heads to Japan hoping to get the battle that he needs to get over this irritation, but causes more trouble by attacking everyone in his way and forcing Zatch to both fight to save others as well as fight this Mamodo warrior. Although Zatch nearly fails against him, his own resolve and feelings to become a kind king finally forces Bari to realize his own dream, to become an undefeated "strong king", giving his bookkeeper relief that Bari may finally be finding his own way. Bari is also the first mamodo to overwhelm Zatch and Kiyo in terms of raw power.
In episode 92 it was revealed that Dr. Riddles asks Bari to help him battle the ancient mamodo but declined because Zatch was also going to help Dr. Riddles. Continuing his own journey, Bari soon faces similar odds against another extremely powerful Mamodo, the dragon Elzador who utterly dominates Bari in the beginning. Using his own resolve and feelings, Bari is able to defeat the monstrous opponent but takes massive damage in the process. Elzador, for this feat, congratulates Bari on this victory. Sometime after, Dr. Riddles requests Bari's help again to deal with Faudo. To the Doctor's surprise, Bari agrees to help. Once Bari and Gustav arrive (by Apollo's plane) at Faudo's location, they use Zonis and Gigano Zonis to fly closer to Faudo, then Digaru Doruzonis to drill through Faudo's neck and enter his body. They arrive just in time to help Zatch and his group. Using all he learned, especially the knowledge he had gained from his battle with Elzador, to become a strong king, Bari finally defeats Keith by destroying his book. Yet as a final act, his opponent placed a trap keeping Bari locked away from the rest of the team. Zatch attempts to disarm the trap at the cost of his own life while asking Bari to be the one to defeat Zeno. However, Bari decides that it is Zatch who should defeat Zeno. Bari gives his life instead to allow all the others to pass. To prevent his death, Gustav allows Sunbeam to burn Bari's book while noting that Bari, while not becoming a strong king, became a strong Mamodo capable of striking even a king.
In between Bari and Zatch's second meeting, Bari has undergone multiple battles and has receives numerous permanent scars. He has even lost one of his horns. His biggest battle was with one of the legendary dragon brothers, Elzador (the weaker of the two). Elzador was originally of the four mamodo children who only adults could beat. The others being Zeno, Brago, and Elzador's brother Ashuron. Elzador is the one who gave Bari his scars; however, Bari rose triumphant. (Chapter 239 page 4).
Anime: As in the manga, Bari arrives at Faudo to help Zatch, and encounters Keith. When he does, they immediately start fighting. During the fight, Keith reveals that he beat Bari in the last contest they had, a Potato Tempura eating contest. Both he and Keith survive, however.
Bari is next seen lending Zatch his power in the final battle against Clear Note. His last appearance is in a school in the Mamodo World, in a classroom with a gloomy atmosphere (the students accompanying him being Keith, Rodeaux, and Tsao-Lon). His restored body retains the scars that he got in his
battle with Elzador. Gustav appears to have returned home after Bari's book was burnt and was shown to be praying hard for Zatch's victory against Clear.
Bari and Gustav's relationship resembles that of a strict father and a rebellious son but Bari appears to (somewhat grudgingly) respect Gustav for his immense knowledge. Despite often acting as a disapproving father, Gustav praises Bari when Bari sacrifices himself to save Zatch and the others, saying that even though Bari had not become the king of the mamodo world, he had become a man that is powerful enough to even strike the king. He cries silently and bids farewell to Bari, which causes him to cry as well, promising that he will never forget him.