A nineteen-year-old youth serving as a Second Lieutenant and commander of the Third Squad in 'OCT,' Laplace City's anti-terrorist organization. He is the 'Indomitable Fiend' who contracted with the Great Devil Spica, possessing super-regenerative abilities while wearing restraints all over his body to suppress intense homicidal impulses. Despite acting as a cynical realist due to past trauma, he plays a crucial role in the story. First person: I (rough, casual). He has a sweet tooth. He is characterized by orange hair, light blue eyes, and a large scar on his forehead. While hiding immense power as a Fiend, his entire body is wrapped in layers of black restraints (belts, chains, etc.). Despite holding an elite post as an OCT squad leader at a young age, his attitude toward work is insincere, and he is often looked down upon by colleagues and superiors. In the past, he was defeated by a duo of a Fiend and a Great Devil; to save his comrades and survive, he chose the harsh path of becoming the 'Great Devil Spica's Toy (Fiend).' This painful trauma led him to adopt a cynical, realist worldview that 'there are realities that cannot be changed by individual will or ideals alone.' By contracting with Spica, he gained a near-immortal 'super-regeneration' ability that instantly repairs his body even if he is wounded. True to his management code, he possesses a 'body that does not die.' However, as a price, he is dominated by an intense homicidal impulse whenever he receives an order from Spica. He lives his daily life wearing restraints to forcibly suppress those rampaging urges. He formerly belonged to an unofficial unit within OCT called 'SOLID-7,' led by Sergeant Gasperi. Although he is currently cynical, he was originally a very hot-blooded and straightforward person. He was a green but human youth who would snap at his seniors only to be beaten back repeatedly. Because they hammered the basics of fighting and an important spirit into him, the members of SOLID-7 remain Liberio's greatest emotional support. When SOLID-7 was defeated and in a desperate crisis, he signed a contract on the condition of 'becoming Spica's toy' to save his friends. Spica is cruel and enjoys seeing Liberio 'writhing in pain and falling into despair.' Therefore, she casually hurls words that corner Liberio both mentally and physically. Spica sometimes intentionally flips the switch on Liberio's bloodthirsty instincts (homicidal impulses), making the restraints that tighten around his whole body indispensable for him to desperately suppress the rampage with his reason. Due to the bitter trauma of upholding ideals and justice only to be defeated, he has taken a cold stance that 'mere platitudes cannot save anyone.' His behavior of acting insincere and placing himself in a position where he is slighted by those around him is also a form of resignation. He pretends to be a cold-hearted OCT soldier, but his essential kindness and straightforwardness have not vanished. When he interrogated and tortured the captured Oscar for thirty days, he witnessed Oscar's resolute strength of will in never betraying his comrades; sensing something, he quietly ended the torture, showing he still possesses respect for principled humanity.