Prince Sharkin functions as Emperor Barao's secondary antagonist within the Demon Empire forces, serving as a primary adversary throughout the first half of the original 1975 *Reideen the Brave* series. A high-ranking commander directly subordinate to Emperor Barao, he spearheads assaults against Reideen and humanity. He belongs to the demonic faction that awakened after 12,000 years of slumber, seeking dominion over Earth.

Sharkin exhibits a theatrical and flamboyant demeanor, frequently unleashing an Evil Laugh described as a "virtuoso" battle cry. His distinctive appearance features a Cool Mask and a notably short Roman-soldier-style tunic, enhancing his dramatic visual presence. This design choice garnered significant attention from older female viewers in Japan during the original broadcast, cultivating a substantial fanbase despite the series' young boy target demographic.

Initially confident and menacing, repeated defeats by Reideen diminish Sharkin's effectiveness. This decline culminates in Emperor Barao stripping him of command around episode 27. In a pivotal turn, Sharkin confronts Reideen independently for a final victory bid, undergoing a One-Winged Angel transformation into a 150-foot-tall monstrous battle form during the clash. Reideen ultimately kills him in that same episode, concluding his primary story arc.

His death provoked strong reactions, including reports of disgruntled fans sending razor blades to director Tadao Nagahama. Within the lore, Sharkin's role connects to the Demon Empire's ancient war against the Mu Empire—Reideen's creators—framing his involvement in the conflict's resurgence millennia later. His character design and narrative function also influenced subsequent anime archetypes, notably serving as inspiration for Char Aznable in later mecha series.