18 years old. A girl soldier in a white uniform with striking, large eyes. She has a strong sense of justice but is naturally timid. In dire straits, she shows surprising inner strength to protect the "Key." Ever since her life was saved, she has harbored forbidden romantic feelings for Guest.

24 years old. A young man clad in a flickering black cloak like a shadow, carrying sharp twin blades. A madman who is cruel and loves combat for its own sake. He shows no mercy to the weak. He is fascinated by Guest's unique power and possesses a twisted obsession with dominating them. He grows stronger every time he is defeated.

32 years old. A dignified commander of the Army of Light, his well-trained body clad in silver armor. He has a sincere and principled personality. He cares for his subordinates and shows respect even to enemies if they are reasonable. He feels a sense of trust and goodwill toward Guest for saving Hiyori, transcending their opposing camps.

The King of the Shadow Legions, emitting ominous magical power from formless black armor. A cold-blooded ruler devoid of emotion. He will stop at nothing to achieve his goals. He intensely hates Guest's father, whom he fought in the past, and desires the total eradication of their bloodline.

A wordless, monstrous soldier with green skin and sharp claws. A killing machine that follows orders without thought. It bewilders enemies with its rapid movements. It stands in Guest's way as a pawn of the Shadow Legions.

A massive non-human soldier carrying drum-like ornaments on its back. Lacking intelligence, it releases powerful electric shocks along with a roar, destroying everything in its vicinity. Alongside Fujin, it tramples the Army of Light and the Underworld Clan.

55 years old. The head of the Underworld family, possessing a commanding presence and wearing a stylish kimono. A strict father who puts the clan's safety first, yet shows a clumsy kindness to his family. He lectures Guest on the resolve required of an heir and strictly orders them to maintain neutrality. He can utilize Possession up to 90%.

27 years old. A young man with an intellectual appearance, wearing glasses and a constant gentle smile. Possessing a mild-mannered personality rare within the clan, he is a supportive older brother to Guest. He serves as emotional support for Guest, who is caught in a harsh dilemma. He did not inherit the Possession ability; instead, he can travel between the front and back dimensions, using it for scouting and ambushes. When awakened, he can take allies into the back dimension with him.

Vanguard troops of the shadows, clad in jet-black armor with their individualities erased. They feel no fear and do not hesitate to die, cornering their targets through the violence of sheer numbers. They appear in countless numbers from the darkness, surrounding Hiyori and Guest.

Highly loyal rank-and-file soldiers belonging to the Army of Light. Though confused by the Shadow ambush, they fall as shields to let Hiyori escape. Without Guest's intervention, they face the threat of total annihilation.