Yuto is one of the characters in the Yu-Gi-Oh! ARC-V anime. He is the Xyz Dimension counterpart of Yuya Sakaki (Standard Dimension), Yuri (Fusion Dimension) and Yugo (Synchro Dimension), and one of Zarc's reincarnations.
His name was first mentioned on-screen in episode 21; before that, his name was displayed as Unknown on-screen and he was called the Dark Duelist in promotional materials and the Dark Masked Duelist by characters in the series. He is a Duelist of the Resistance, despite his peaceful and harmless nature. After he lost to Yugo in a Duel, Yuto was absorbed into Yuya - still having strange reactions whenever prompted by an external stimulus. One such reaction eventually allowed him and Yuya to communicate mentally.