Ryuga, a martial artist within the King of Fist’s Army, stands as a pivotal ally to Raoh in their campaign to dominate a fractured, post-apocalyptic world. His Mount Tai Sirius Fist (泰山天狼拳, Taizan Tenrōken) channels energy from the isolated star Sirius, enabling surgical strikes that inflict opponents with a bone-chilling cold before their demise.

Eldest sibling to Juza and Yuria, Ryuga outwardly aligns with Raoh’s goal of imposing order through strength. Secretly, he seeks to liberate Yuria from the enigmatic "King," a plan shattered when Juza discloses her suicide to evade captivity under the warlord Shin. Despite this, Ryuga remains loyal to Raoh, pivoting toward crushing rival factions and purging disloyal soldiers to fortify their regime.

Guided by a belief that only unrelenting force can forge stability, Ryuga enacts Raoh’s will with calculated brutality. He clashes with Kenshiro, Raoh’s brother, after abducting Toki—a fellow Hokuto Shinken master—to draw Kenshiro into combat. Though mortally wounded in their duel, Ryuga concedes Kenshiro’s capacity to restore equilibrium to the world with his final breath.

Torn between ruthless pragmatism and lingering ties to his shattered family, Ryuga’s journey is shaped by Yuria’s loss and the merciless demands of a lawless era. While his tactics mirror Raoh’s vision of conquest, his drive stems from personal tragedy and a fractured hope to rebuild order from chaos.