In the year 2032, a nameless amnesiac awakes in a world wrought by devastation: a cataclysmic explosion known as the "Blaze," or the "Great Heat." Unable to speak, the boy is confronted by a mysterious, red-eyed man with wings. According to the man, simply named the Archangel, the boy is responsible for the state that now plagues the world. After giving him an oddly shaped gun, the Archangel points to an ominous edifice in the distance: the Neuro Tower. His instructions for the boy are simple: venture to the tower's bottom and obtain salvation. Dextera begins the story constantly emoting confusion, having lost his memories prior to the Great Heat. A strong desire to rid himself of a dreadful sense of guilt encourages him to push deeper into the Neuro Tower's depths, though he does not know the source of the guilt. His ignorance regarding the current world makes Dextera somewhat naive, as he believes almost everything he is told by the Archangel without question. Even when a frustrated Archangel chastises him for failure, Dextera passively withstands the verbal abuse and continues to seek comfort and guidance from him. Dextera was born one of a pair of conjoined twins that shared a single heart. Both were inducted into the Koriel faction of the Malkuth Order, Dextera as Number 12, and his older brother as Number 13. Dextera in particular proved to be especially valuable to the Malkuth Order, for, even at a young age, he showed wavelengths that were similar to that of the Absolute God's. This allowed him to almost hear its voice. However, the twin's single heart could only support one of them being awake at a time, even with the assistance of a life support machine. As the two brothers aged, the heart could no longer sustain both bodies. In order to preserve the life of at least one brother, the other had to be cut off from the body, killing him in the process. Number 13 self-sacrificially volunteered himself to die in place of Number 12. Number 12 protested profusely, wishing to die alongside his brother, but he was tranquilized by the Koriel early into his fit. The next time he awoke, Number 12 was alone, accompanied only by a scar on his hip and a sense of guilt that followed him into late adolescence.