Ν-No.13-

""Hahahahaha! Ragnaaaaa! Ragna! Ragna! It's impossible, Ragna! Nothing will change! You can't change anything! Hahahahahaha!""

ν-No.13-, more commonly abbreviated as Nu-13, and also known as the Sword of Hades, is a Boundary Interface Prime Field Device who is modelled after Saya and lusted after Ragna the Bloodedge, hoping to fuse with him to become the Black Beast. As of BlazBlue Alternative: Dark War, she has discarded her identity as Nu-13 and has chosen the name Juusan (十三).

Nu first appeared in BlazBlue: Calamity Trigger, and was absent for BlazBlue: Continuum Shift only appearing as Lambda's Unlimited Form. She reappeared in BlazBlue: Chrono Phantasma and onward. As Juusan, she was revealed for BlazBlue Alternative: Dark War on August 13th, 2021.

Appearance
Nu-13 is a fragile and thin girl with pale skin, large, sunken red eyes, and gray hair. Most of her hair is worn in a very long ponytail, the end of which is attached to a sword-shaped metal object. On her face is a seithr regulator, which she wears as part of an eye patch. The symbol for a Prime Field Device is tattooed between her collarbones.

When in standby mode, Nu's clothing is a simple light blue one-piece jumpsuit with short leggings and long sleeves which wrap around her middle fingers in a way similar to bridal gloves. There are metal harnesses on her jumpsuit on the nape of her neck and under her breasts. Over this, she wears a white and blue cloak with various rings attached to it. These rings are adorned by red talismans with various symbols on them. The cloak has a huge collar, held upright by a metal piece imprinted with Nu's Prime Field Device symbol.

Nu's battle gear is very similar to that of a mecha. Her face is covered by a visor with horn-like antennae and a single, glowing red eye. Over her jumpsuit, she wears a harness which is attached to a blue jewel and to her shoulder guards. These shoulder guards are blue and white, with a gray part on the nape of her neck, and there are two seithr regulators on the back of each shoulder. The shoulder guards are attached to her arm guards, which have small blades similar to her swords mounted on them. Her battle gear's most distinctive feature is the plate armor covering her legs. These armored leggings are mounted with blades that serve as weapons for her. Nu's hips, upper arms, and armored leggings have glowing green lights on them.

Nu is able to telekinetically control eight swords, which she uses as weapons in addition to the blades on her legs and forearms. These swords often float behind her in a pattern similar to wings. While in her battle gear, there is a small black marking in the shape of a sword on Nu's jumpsuit.

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. She carries a small pocket watch with her, likely to time her uncontrollable collapses.

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, lusting after him and breaking her mechanical language. She will vocally call out to him with sexual 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 the Grim Reaper 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 that appear in Japanese media.

Following the events of Central Fiction, Nu discarded her identity and chose a new name for herself: Juusan. Noel and Lambda would soon become known to her as her sisters, although she has learned to be wary of Noel's cooking. Instead of staying as an emotionless husk, Juusan has developed her own emotions and personality. She is cool, calm, and aloof. She does not like to dwell on the past but has had time to reflect on her philosophies, such as her denial in the belief of a God. 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. She sees the suffering of the Observers trapped within their Phantom Fields and, if given the opportunity, Juusan will save them from their despair. Having ventured to different time periods as part of the Phantom Fields, Juusan has her preferences - she dislikes Fields set before the Dark War as she is unaccustomed to their filthy air. 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.

Powers & Techniques
As a Boundary Interface Prime Field Device, Nu is completely immune to the effects of seithr 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.

An ability that Nu excels in using is deploying her ', floating black spaces that deploy a myriad of blades; in gameplay, this is her Drive, '. There are no limits to the black blades she can produce with this ability, some of them ranging from typical swords to blades that run along the ground, catching at her opponent's feet. 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. Even when she is damaged or in pain, Nu's will to fight through to kill her opponents means that she is unstoppable. Even the Arcus Diabolus: Bolverk has not enough stopping power in its charges to stop Nu from hunting her enemies.

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. After absorbing Take-Mikazuchi's core, Nu is a threat that only the strongest can eliminate - she can fight evenly against Jubei and Hakumen, two of the Six Heroes, but her deteriorating mental state makes her an easy target for individuals such as Yuuki Terumi.

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.

BlazBlue: Calamity Trigger Official Site Profile
''A young girl who appeared from the "Cauldron" buried deep within Kagutsuchi. Nothing about her appearance suggests who she may be. ''

BlazBlue: Chrono Phantasma Official Site Profile
''Nu-13, who resurrected by her own will in order to fuse with Ragna. Hazama calls her the "Sword of Hades." Rebuilt by Hazama, she once again stands before Ragna. ''

BlazBlue: Central Fiction Official Site Profile
''A young girl who appeared from the "Cauldron" buried deep within Kagutsuchi. She is a Boundary Interface Prime Field Device fitted with the Phenomenon Weapon "Lux Sanctus: Murakumo." She has appeared once again in order to fuse with Ragna, but things seem a little different from before.  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. ''
 * Story
 * Personality

BlazBlue: Central Fiction Library Entry
''A young girl who appeared from the cauldron buried deep within Kagutsuchi.
 * ν-No.13-

''She is one of the three sacred units, the Murakumo Unit. She is both the last Nox Nyctores, and the core of a Black Beast. Her actions and personality is machine-like and because of Saya's soul, she shows emotion while in the proximity of Ragna.

''She's also a fragment of the Black Beast's shell, which houses Ragna, and by fusing with him, they become the Black Beast that brought terror to the world. She's also known as the 13th Prime Field Deice, or the Blade of Hades.

''Although she fell into the cauldron once, she was revived as Lambda, after being retrieved by Kokonoe.

''Now she roams as the Blade of Hades, in hopes that she might fuse with Ragna once more. All according to Hazama's plan…

''Fusing with Noel, Nu gains the power of the Successor to the Azure, bringing down the Amaterasu Unit to the realm of mortals.

''Hazama refers to Nu by this name as she's being smelted in her Cauldron, at the end of the story of ‘Continuum Shift.'
 * Sword of Hades

BlazBlue: Cross Tag Battle Official Site Profile
''A young girl born from a giant apparatus known as the. She makes decisions in a mechanical manner, yet sometimes shows moments of intense emotion.

''Quick yet long-range projectiles can be called out with one button by this shooting character. Take control of the screen, and overwhelm the opponent without letting them get close! ''

BlazBlue 10th Anniversary Official Site Profile
''A mysterious young girl who emerged from a giant apparatus called a "Cauldron". She makes decisions in a mechanical manner, but in front of Ragna the Bloodedge will show a girlish side to herself.''

Appearances in other Media

 * The mobile game Mabinogi Duel stars Nu as a playable card.

Trivia

 * In the BlazBlue 10th Anniversary Character Poll, Nu placed 9th out of the 84 candidates. She scored one place above Es and one place below Noel Vermillion. She had 2,784 votes.
 * Nu's birthday is New Years Eve.
 * Nu was born the same day that she fought against Ragna in the climax of BlazBlue: Calamity Trigger. This makes her the youngest character in the series as she is less than a few months old by the time the C-series ended.
 * All of Nu's movelist is named after various kinds of cars. She shares this with Lambda.
 * Nu shares her English voice actress, Cristina Vee, with Saya, Noel, Mu-12, and Lambda.
 * As Nu was absent in BlazBlue: Continuum Shift, Lambda replaced her and the two have a near identical moveset. In BlazBlue: Chrono Phantasma, their movesets were combined as Lambda was absent - Nu could switch between her traditional moveset and Lambda's using the Face Lift move. In BlazBlue: Chrono Phantasma Extend, Lambda was reintroduced and Nu lost Face Lift in her moveset as well as the ability to use any of its associated moves.
 * Nu's lost of Face Lift is the only time that a character has had a move removed and not replaced with something different.
 * In BlazBlue: Continuum Shift Nu is Lambda's Unlimited form.
 * In an interview with series creator MORI Toshimichi in the BlazBlue: Central Fiction Official Setting Material Collection, he stated that he did not originally wish to resurrect either Nu nor Lambda, but only did so because of the nature of fighting games.
 * Nu was present in the BlazBlue Alternative: Dark War opening over 6 months before her official debut as Juusan.
 * Nu is illustrated in the following Grimoires for BlazBlue Alternative: Dark War:
 * 無垢なる願い (Innocent Wish).
 * 疑似観測者 (Pseudo-Observer).
 * 新たなる邂逅 (New Encounters).