Zagi is one of the major antagonist and assassin hired to kill Flynn Scifo in Tales of Vesperia. Zagi is a member of the "Red eyes" as they are referred to early on, due to the mook charicter signiture red eyes, on but is later revealed to be a member of Lethiathans claw, one of the five master guilds of the Dhangrest Union. Zagi personally is a violent sociopath who only seems to draw pleasure from fighting and killing strong opponents leading to his role as an antagonist targeting Yuri Lowel.
Zagi is an elite assassin Yuri Lowell meets early in the story. Deluded and somewhat insane, the party fights him a total of five times in the story. He is first encountered in Zaphias's imperial castle, where he mistakes Yuri for Flynn Scifo, though it is never revealed who sent Zagi to assassinate Flynn initially. He is defeated by Yuri, who also protects his new ally Estelle from Zagi's attacks. This defeat leads Zagi to develop a personal grudge against Yuri throughout the story. Zagi battles Yuri and his allies again on the ship leaving Capua Nor, incidentally preventing the party from pursuing Ragou and Barbos, who escape on an emergency boat.
He is defeated again and caught in the ship's explosion. However, despite his seeming demise, he returns yet again in Nordopolica's coliseum, interrupting a battle between Yuri and Flynn. In this encounter, he sports a seemingly-mechanical left arm equipped with a powerful bodhi blastia. He informs Yuri he was the one who gave this to him, meaning his arm was lost after the previous battle. The blastia allows Zagi to absorb magic artes but breaks when he absorbs too much magic, leading to his defeat.
Zagi appears for a fourth time in the control room of the mobile fortress Heracles. He attacks more fiercely than before, poisoning himself to add new attacks to his repertoire, but falls yet again to the party's strength. After his defeat, he returns and attempts to continue his fight with Yuri even after being shot out the window by Yuri's assault. However, before Zagi is able to do this, Yeager appears with Gauche and Droite, who force Zagi out the window once more. Zagi's fifth and final appearance is in Tarqaron's destroyed coliseum. He blocks the party's progress with a seal that can only be removed by taking his prosthetic left arm, ensuring the party would fight him with their full strength. At this point, his physical appearance alters dramatically: his hair now drooped around his head, his shirt torn, bulging veins visible on his shoulder and chest, his blastia arm with a new design around the forearm, his voice distorted, and covered by a crimson aura.
In battle, Zagi uses two dagger-like blades, held in a reverse grip. He fights with various, fluid movements, such as spinning around and dashing upward or downward. He can also throw his knives like boomerangs. In later battles, his attacks can also inflict paralysis on their victims. Zagi carried a vial of poison with him when he attacked the group on the Heracles. However, he used it on himself, enabling him to blow poisonous clouds at his foes. Zagi's blastia arm opens a whole new range of abilities for him. He can fire powerful beams from it or use it to shield himself from attacks. Doing so, however, leaves him exhausted and vulnerable to attacks afterward. In his final battle with the party, it also acted as a key to a magic seal blocking the party's path in Tarqaron. His mystic arte, Shining Blastia Field, blows his opponents away from him while he overloads the blastia in his replacement left arm. The overload shoots a beam of concentrated aer into the air, which proceeds to rain down upon the party. Coincidentally, he shares some of his attacks with Repede.
Project X Zone 2
Zagi makes an appearance as a non-playable boss character in the crossover video game; Project X Zone 2.