She is revealed to be Horizon Ariadust's original body with an automaton mind and she has Horizon's old memories. Her designation is P-01m.
She uses Toukichirou Hashiba's automaton body to interact with the outside world since Horizon's body was so badly injured Nobunaga herself can only be active for two hours a day.
She is the real key of the Genesis Project in order to destroy destiny's personality. Nobunaga will be linked to destiny via the second moon (the ether one), Nobunaga will act as a vessel for destiny's personality, and she will be executed.