Shadow Moon is the dark rival and twin brother-like counterpart of Kotaro Minami in Kamen Rider Black. A central antagonist in the series, he serves as the chosen successor of the Gorgom organization and embodies the tragic conflict between humanity and evil control. Originally known as Nobuhiko Akizuki before his transformation, Shadow Moon is a powerful cyborg-like being with a commanding presence, dramatic fighting style, and deep personal ties to the hero, making him one of the series’ most iconic and emotionally significant figures.