Reginald Kastle, known as Ryoga Kamishiro (神（かみ）代（しろ） 凌（りょう）牙（が）, Kamishiro Ryōga) in the Japanese version and nicknamed Shark, is a character in the Yu-Gi-Oh! Millennium Duels video game. This is a video game depiction of Reginald Kastle, a character from the Yu-Gi-Oh! ZEXAL anime.