In her regular form, Nacht takes the shape of a twisted rapier with a skull by its handle. Her Hero Form armor is colored black and has fish-like motifs with fins and scales. In her human form, Nacht wears a black, goth-loli dress and had blue and blackish hair in a hime-cut style. Her eyes are particularly dark and iridescent, and gave off a villainous hue.
Nacht has a very flippant and critical personality who is constantly questioning Haunted's decision making but nonetheless decides to remain under his usage as she loved his corroded persona. She is very informal, most likely due to her extended time with her wielder, and very prideful of her abilities. Similar to Lapis, Nacht is very clingy and gets jealous if Haunted praises another blade.
At some point in time, Nacht had accept Haunted as her wielder while apparently some quarrel had been had over her ownership with other Valhalla members.
Hero Summoning Arc Edit
Nacht wakes up after Haunted and Mari's conversation during the latter's visit to deliver the magical heritage fragment. Haunted's obsession over seeing Mari distressed annoys Nacht to no end as she complains at how she was awoken from her sleep.
Witch's Struggle Arc Edit
Haunted is despondent at how he had miscalculated the Inquisition's interference and how Mari had been captured by them. Nacht criticizes his rash decision making but nonetheless, Haunted devises a plan to get himself into the academy to "rescue her". Nacht is drawn out when Takeru engages them in close combat and Haunted accesses her Hero Form to match him. Nacht's abilities are able to cause enough trouble for Takeru but her magic is temporarily canceled by Ouka's crimson ore grenade. Takeru eventually stands again to face Nacht and Haunted and she activates her intrinsic magic to finish him off. Berserk Enchant is however counteracted by Takeru and Lapis utilizing Mari's own magic to overpower the two. Nacht is beaten back and Haunted soon retreats with her following him.
Valhalla Calling Arc Edit
Nacht and Haunted return to Valhalla's headquarters near the Magic Academy where she walks around in her human form, something she preferred over being sheathed in anti-magic material. Hearing that Mari, Takeru, and Lapis were retrieved by Orochi and Kanaria, Nacht urged Haunted for them to kill Takeru and Lapis after their previous defeat. Nacht however witnesses a rare moment of anger from the usually aloof but openly emotional Haunted, who in a mix of joy and anger, states his interest in keeping Takeru alive for now.
Haunted's reasons to keep Takeru alive is revealed later on when Haunted saves Takeru and heals his injuries when he was surrounded by pureblood wizards in his chase to rescue Lapis. Haunted reveals that Takeru embodies everything he hates but is unable to deny that Takeru has defeated him before and wishes to kill him in another fair duel. Haunted brands Takeru as an embodiment of hope, his greatest nemesis, and leaves him to retrieve Lapis and hopes to see him again on the battlefield after the two slaughter Elizabeth's troops.
White Escape Arc Edit
Nacht joins Haunted during Mother Goose and Orochi's visit to Sougetsu where she and Haunted immediately assault Sougetsu after the two parties violently separate from each other. Sougetsu blocks a swing from Nacht with Innocentius but the two both run away from Orochi's Ama no Habakiri technique.
Heretic Alliance Arc Edit
Nacht observes Haunted's interference with Kiseki's stasis after his outburst at how the happiness she was simulated dreaming was fake and it demanded correction.
Witch Hunt War Arc Edit
Nacht joins Haunted in his casual killing spree of a town near the Inquisition Headquarters and informs him of his tardiness after they witness an explosion near the Antimagic Academy. As Haunted screams in sadness at how his fun plans were ruined, pillars of flesh began rising from the ground and Haunted realizes that his merriment could still be salvaged. Nacht informs him that Takeru has bested Orochi and Haunted quickly moves out to find the Kusanagi siblings.
Call of Twilight Arc Edit
Nacht accompanies Haunted in interrupting Takeru and Kiseki's heated conversation, which prompts the latter to retreat. Haunted and Nacht's opponent however switches from Takeru to Kurogane, who delays Haunted. However, Kurogane's first showcase of actual emotion inspires Haunted to fight him on serious grounds, whereas in the past, he found him a boring opponent.
Promise of Dawn Arc Edit
Nacht was used in conjunction with Haunted's Sacred Treasure to combat Kurogane to the best of each other's abilities with full intents to slay the other. Haunted's victory was all but assured after Kurogane was unable to finish him off after utilizing Maximilian's intrinsic magic but Kyouya's unexpected interference has him obliterated. Haunted however utilizes his last remaining reserves of life to come back one more time to settle his score with Takeru after the latter returns from slaying Sougetsu and he brandishes Nacht once more to end their feud.
It is revealed that Haunted and Nacht were allowed to live after being defeated in their duel against Takeru. The two were separated where Haunted was placed into a maximum security holding facility while Nacht was encased into anti-magical bindings. Both were inactive for 5 years before Takeru confronts Haunted on the means to find a way to cure his sister. Haunted admits to being privy towards this information and promises to share it, but only after Takeru granted him death and killed him in their final duel. Nacht is brought out for the last time and the mad duo are presumed to have been slain as the After-Story epilogue shows Takeru and his platoon heading towards a lead.
Magical Heritage- Dáinsleif: A top-class blade that excels in debilitating its opponents as well having a "similar" effect for its user. Dáinsleif's power limited its opponents with its residual strikes as well as weaken their enemies with recovery-inhibiting abilities while it could also damage its user's own mentality to strengthen them. Haunted was able to best use its flexible blade to parry more effectively.
Intrinsic Magic- Berserk: Nacht's magic that gradually wears down on its user's sanity to grant further strength and magic. It is unknown if Haunted's mental condition is because of his continued usage of Nacht.
- Hjaðningavíg's Bloodbath- Berserk Enchantment: Nacht's empowering ability that temporarily, fully deteriorates her user's mind and spirit to exponentially increase their strength and speed.
Lingering Strikes: Nacht's attacks leaves residues of its strikes in the space that it landed, harming those who make contact as if the left-over attack was the one that landed. These attacks persist in the air for an indefinite amount of time but exist as traces of magic.
- Lasting Wounds: The strikes that actually land retain a similar effect as in that they cannot be properly treated by regular means or with basic magic.
Hero Form: Nacht's Hero Form grants defense and increased strength and agility, further empowering her user and her abilities.