The Marb Empire is a land ruled by two supreme authorities: the Emperor and the Pope. Ilha is born as the heir to both bloodlines, destined for greatness. However, a political conspiracy leads to his mother’s murder, and Ilha is framed for the crime. He is stripped of his status, exiled from the empire, and sold into slavery. For ten grueling years, he endures a life of servitude and hardship, barely surviving.

His fate changes when he meets Sio, a young girl from the demon tribe. The demon tribe is persecuted by the empire, and Sio’s entire clan was massacred by imperial forces. Her grief has hardened into a burning desire for revenge. Moved by her unyielding fury and refusal to surrender, Ilha finds the will to fight back. He decides to reclaim everything that was taken from him: his freedom, his honor, and ultimately, the imperial throne.

Ilha and Sio forge a partnership bound by a shared enemy. They seek out allies, including the veteran warrior Reyon, who trains them for the battles ahead. The empire’s most feared enforcers are the Seven Sacred Swords, elite warriors wielding immense power granted by miracles. Ilha’s path is blocked by these adversaries, beginning with the relentless Durandal. Ilha is pushed to his limits, suffering defeat and near-death experiences, but he repeatedly awakens new strength to survive.

The conflict escalates when the pair joins a revolutionary army opposing the imperial church. The revolution is led by the giant warrior B.B., a former comrade of Reyon. Ilha and Sio face the leader of the Seven Sacred Swords, the invincible Gram, and are overwhelmed. They are saved by a desperate act from a former enemy, who teleports them to the Demon Continent, Sio’s homeland.

On the Demon Continent, Ilha and Sio seek the power of the Great Spirit to defeat Gram. Sio is subjected to a harsh trial to become the true Flame Priestess, forcing her to confront the trauma of her people’s slaughter. Ilha fights to protect her, clashing with the Seven Sacred Sword Balmung. Tormented by his reluctance to kill, Ilha is possessed by a malevolent spirit. Sio saves him by invoking a pact they made earlier, the Flame Life Vow, which restores his soul.

The final battle unfolds as Ilha, backed by the trust of his companions, confronts Balmung and the remaining forces of the empire. The story concludes with a decisive showdown that determines the fate of the world, ending with Ilha achieving his goal of reclaiming the throne and bringing an end to the empire that wronged him.