Juusan, formerly known as Nu-13, is a Boundary Interface Prime Field Device (an artificial human created to explore the black dimension known as The Boundary) who is modelled after Saya, and chased after Saya's older brother, Ragna the Bloodedge, hoping to fuse with him to become the Black Beast (a monstrous creature that would bring doomsday). After failing repeatedly and been rejected and defeated by Ragna and his allies several times, she has discarded her identity as Nu-13 and has chosen the name Juusan. As Juusan, her attire has changed drastically. She has cut off her long braid and wears bandages over her right eye. Strikingly, Juusan's crest on her clavicle has been replaced by a large 'X'-shaped scar. She no longer wears the signature armor of the Lux Sanctus: Murakumo and instead wears a silver bodice with blue trimming; it has a deep cut and stops at her midriff. Juusan wears matching panties and a large black belt which hangs around her hips - attached to this is a remnant of cloth from her original outfit outside of Murakumo. She wears black thigh-high leggings, white shoes, and black finger-less gloves. Over Juusan's outfit is what appears to be Ragna the Bloodedge's jacket: a bright red jacket with various black belts covering it. It's ripped and frayed over the sleeves, collar, and general body. Some small alterations have been added, such as a clasp around the chest, an ornament on the left side, and a cracked metal plate that covers Juusan's neck. Personality: Although she judges situations mechanically, she will occasionally show moments of intense emotion. She has the highest-priority objective to "be together with Ragna" and towards Ragna alone will act girlishly. To almost everyone, Nu is cold, mechanical, and apathetic. She is solely focused on her mission to fuse with Ragna, and will not allow anyone to come between her and that objective. When away from Ragna, Nu's speech pattern is robotic, using complicated and professional language, and vocally exclaiming when she is loading or commencing the extermination of a target. Like this, she will often analysis her opponents and assign them warnings, coldly assessing their strengths from a glance. But to Ragna, everything changes. When around him, Nu is filled with emotion, chasing after him and breaking her mechanical language. She will vocally call out to him with wanton innuendo, taunt him about his darker feelings, and threaten to kill him, all while baring a smile filled with glee. It appears her feelings of "love" towards him are genuine, but love to Nu is simply fusing with Ragna to become the Black Beast - nothing more or less. She won't allow anyone else to touch him, she only wants Ragna to herself, and as far as she is concerned, everyone else is an obstacle in the way of her happiness. Eventually, Nu's mechanical expressions faded away, and she is nearly always filled with intense emotions, particularly on killing others and seeking Ragna. She went insane from not being with him, and would do quite literally anything to become one with him. She would even defy the orders of those who command her, being derogatory and showing a sharp tongue to anyone who isn't her love. Nu has no hobbies, bar thinking about Ragna. Nu is part of the yandere trope of characters. Following the events of BlazBlue Central Fiction, Nu discarded her identity and chose a new name for herself: Juusan. Instead of staying as an emotionless husk, Juusan has developed her own emotions and personality. She is cool, calm, and aloof. Juusan is fond of animals, like cats, and will give up some of her own food to them. Juusan hates remembering her past life and she has some semblance of self-hatred. It appears that she is searching for Ragna, and some of her old salacious feelings still lurk beneath. Despite this, she aims for some normality and to be rid of those darker feelings that permeated her identity as Nu-13. As a Boundary Interface Prime Field Device, Nu is completely immune to the effects of seithr (the energy that fills the Boundary, which can corrupt living beings) and can freely roam the Boundary with no consequences. Since she is one of her species that is modelled after Saya, she has incredible Ars Magus aptitude, merited by her ability to use the Lux Sanctus: Murakumo. When activated, Nu has its bladed armor and floating eight blades at her disposal, and she excels in masterfully using them against her opponents. Even without this ability, Nu is blindingly fast and strong, capable of various acrobatics and blows strong enough to knock opponents meters into the air. Nu has a Life Link with Ragna - this means that neither can die unless they both die in a similar time frame; because of this, both are unconventionally immortal. Even without her life link, Nu is extraordinarily difficult to kill, being able to regenerate her damaged body at inhuman speeds. As this prime field's mentality has begun to unwind, she has become more vicious and willing to destroy. She is far easier to annoy and her quickness to anger in her pursuit of Ragna is a weakness that is easy for strong opponents to exploit. Following the events of Central Fiction, Juusan has discarded the use of Murakumo and only keeps one of its swords by her side, using it like a traditional blade. Somehow, she has gained the use of Gigant: Take-Mikazuchi as her new Nox Nyctores of choice instead, having gained the ability to summon it at will. Using her inherent abilities as a Prime Field, Juusan is able to enter into a Phantom Field of her own volition while not experiencing the distorting essence of the Boundary. While she has begun recovering mentally, Juusan has gained new weaknesses. She has phases where she will go briefly unconscious against her will and her right eye will occasionally throb in pain.