Ada is Carl's older sister, and frequently doted on him when she was still human. Due to her affection, Carl idolized her, and frequently spoke highly of her to his friends at school (much to their amusement). One day, for reasons unknown, she agreed to become the subject of one of her father's experiments, but according to the story, there was a possibility Ada was forced. As a result, her body was fused into the Nox Nyctores known as Nirvana. Unfortunately, Carl bore witness to this depraved experiment and now seeks out his father in order to get revenge. Nirvana follows him now as his partner and weapon, acting upon his commands and protecting him. Many of the characters recognize her in her form of Nirvana, though the meaning of that has been left unclear.
In spite of losing her humanity and essentially becoming a puppet, Ada displays an unusual amount of sentience as Nirvana. There are many times where she will act on her own, usually when Carl is in danger or to attack a dangerous adversary. For instance, when Carl first confronts Hazama during the events of Continuum Shift, she attacks him without provocation. She does the same to Noel in another scene, surprising Bang that she could move without Carl's will. She also seems to frequently converse with Carl, who is the only one who is able to hear her (although other characters have doubted this). At the end of Carl's True Story, she acts on her own again in a confrontation against her father, fleeing the battlefield with her brother and Litchi. This surprises Relius, who briefly acknowledges her as "Ada" rather than "Nirvana," having previously only referred to her as if she was a thing.
As Nirvana, Ada has short light blonde hair and blank eyes, with a crack on her left eye; during the Dark War, she had normal eyes much like Ignis. She wears a purple dress with a white collar, a purple hat with a golden ring, separate sleeves, and longer arms that reach almost to her leg.
When she was human, she had slightly long hair, and wore a navy dress with vertical light blue stripes.
Before becoming a doll, Ada was a kind, calm, and cheerful person. She was always very kind to her younger brother. After becoming a doll, she becomes lifeless, but even then, she shows unusually high sentience. It is said by Carl that she is very sensitive about her looks, and in Carl's arcade, when she and Carl encounter Hazama, she seem to have a grudge and hatred towards him.
- Koromaru (Persona)
- Oddly, when Carl is victim of Amane Nishiki's Astral Heat, Ada does not appear; instead, Nirvana is shown as a plush toy.