As a child, Keyaru was a simple and kind boy. After discovering that he is a hero, he sets out to save the world and meets Flare, but he does not realize her true intentions. After being imprisoned, beaten, drugged and raped his behavior changes and he becomes a vengeful and sadistic person. After defeating the demon queen, he use her Philosopher's Stone to go back in time 4 years and swear revenge on Flare. After the time reset, he recovers his memory and he gains new skills by making a pact with the spirits of the stars. He also acquires the skill Toxin Resistance, useful in resisting drugs. Being the healer hero, his main power is Heal, which has many variations and different effects.