Zarc is a character and the central antagonist of the Yu-Gi-Oh! ARC-V anime. He is the original incarnation of Yuya Sakaki(Standard Dimension), Yuto (Xyz Dimension), Yugo (Synchro Dimension), and Yuri (Fusion Dimension).
Originally a pro Duelist with benevolent intentions, Zarc was rendered psychotic because of the dragons' belligerence, his obsession with becoming the strongest Duelist and the foreboding of eventually being defeated, which caused his decision to devastate the civilization of the Original Dimension and mutate into a spiteful draconic being known as Supreme King Z-ARC. During a confrontation against Ray Akaba, Zarc's soul was split into four and reincarnated into four different persons. He is the original holder of the Four Dimension Dragons and, along with Ray, one of the true co-creators of Pendulum Summoning.