Hyoga Akatsuki, revived by Tsukasa Shishio, served as a high-ranking member of the Tsukasa Empire. He possessed short white hair, dark purple eyes often observed squinting, and initially wore a mask to conceal scarring around his nose and mouth after depetrification, though this later healed completely. Hyoga mastered the Kan spear style, requiring a hollow-shafted weapon for optimal use. He adhered to a strict social Darwinist philosophy, viewing the petrification as an opportunity to create a world exclusively for the physically and intellectually exceptional. He deemed the weak or incompetent burdens consuming resources without meaningful contribution, advocating for their permanent exclusion. This ideology superficially aligned with Tsukasa's initial goals but diverged in its extremity; Hyoga rejected reviving any youths as insufficiently selective. He maintained a calm, analytical demeanor and tactical intelligence, reserving genuine respect only for exceptionally competent individuals like his subordinate Homura Momiji, whose actions he termed "proper." Conversely, he treated most subordinates as expendable assets, demonstrated by callously sacrificing men to test for poisonous gas. As Tsukasa's second-in-command during the Stone Wars, Hyoga led attacks on Ishigami Village, challenging multiple warriors and orchestrating a distraction enabling Homura to set the village ablaze. His loyalty was a facade; he secretly plotted to overthrow Tsukasa, recognizing direct confrontation was unfeasible. Exploiting Tsukasa's protective instinct towards his revived sister Mirai, Hyoga feigned an attack on her. When Tsukasa intervened, Hyoga fatally stabbed him and pushed both Tsukasa and Senku Ishigami into a river. Washed ashore with Senku, Hyoga attempted to forcibly recruit him to build a world ruled solely by the strong, threatening torture. Senku created a distraction using concealed petrified birds coated with revival fluid. A severely wounded Tsukasa intervened, leading to Hyoga's defeat via electrocution by Senku and Tsukasa. Imprisoned alongside Homura, Hyoga was transported on the Perseus. Petrified during an attack by the Petrification Kingdom, their statues remained hidden while others were destroyed. Facing overwhelming opposition later, Senku revived Hyoga as a tactical counter against the powerful warrior Mozu. After deducing Mozu's untrustworthiness, Hyoga allied temporarily with the Kingdom of Science. Initially struggling against Mozu's stone armor with an inferior spear, he retreated underwater, rendezvoused with Senku, and received a modified Kudayari-type spear compatible with his Kan style. Armed with this, he shattered Mozu's armor. Moments before both were petrified again, Hyoga acknowledged their mutual threat and expressed willingness to teach Mozu his techniques if revived. During the voyage to America, Tsukasa requested Hyoga be revived to train the Kingdom of Science in modern combat, particularly spear handling. Hyoga agreed on the condition Homura and Mozu also be revived to participate. He subsequently aided the Kingdom's efforts, including scouting and resource gathering in San Francisco, helping fend off alligator attacks. While still believing only the strong deserved revival, his philosophy slightly moderated; he later accepted leaving the statues of the weak intact rather than destroying them.