Arachne is portrayed as a calm and intelligent individual. She rarely, if ever, shows any form of distress other than mild irritation; she showed no irritation when Mosquito told her that BREW was damaged in the explosion and left useless, and even used it as an advantage to trick Shibusen into thinking they still had BREW intact by withholding the true information. Likely due to her abilities, Arachne is not above taking advantage of someone's weaknesses and using it to influence them into joining her. She has done this using the Moral Manipulation Machine on Kim and Jackie, and later on using her powers to influence Soul Eater Evans.
She also, like Medusa, is a sinister individual. She is manipulating and cunning. She also holds disregard for anything she deems unworthy to her or her cause. She rarely shows any visible signs of fear or anger. In the anime, she only shows anger in one instance, in which she expressed her hate towards Death. She also has no fear in creating opportunities with ending his life. She even rigged a facility on the Lost Island in an attempt to end his life.
Arachne also greatly enjoys champagne--the finest vintage. In almost all of her scenes, she is seen drinking one. When she had emerged after 800 years and met with Mosquito, the first thing she asked for was champagne. In the anime, she preferred to drink wine moments after being nearly strangled to death by Asura.
She carries herself in an aristocratic manner, as if she were from a noble stock. This is further supported by the fact that she prefers only the finest champagne. She is almost never seen standing up. Immediately after awakening, she was quickly seen atop a golem watching over the ongoing battle. When she wished to retreat, instead of simply walking away, she was carried off by Giriko. She was welcomed by her butler while walking on a red carpet and is driven by him in a luxurious limousine.
She seems to be a power-hungry individual. Her goal is to replace the World Power that is Shibusen and become the "Mother Of All".
Like her sister, Medusa, Arachne also seems to express particular interest in "madness", eventually becoming madness itself within the Manga, while in the Anime, Arachne is instead allied with Asura but still plans to use madness created by Asura for her own goals.
Arachne has an extremely pale and flawless complexion, making it appear like she’s almost constructed entirely out of porcelain. She has a curvy figure, with very large breasts, a thin waist and wide hips. Her facial features comprise of long dark black hair, worn in an upwards manner with two long strands that frame either side of her face, and eyes that have both completely grey irises and pupils, each containing a black spider web pattern.
Her typical clothing consists simply of a long black sleeveless dress; however, this dress is incredibly long, in that it completely conceals her feet, while ending in eight small trailing pieces of fabric like the legs of a spider. A narrow black band encircles her neck featuring a small spider emblem that lies at its front and eight extensions that protrude outwards upon the back, with four emerging from either side. Spider web netting branches the gap between the band and the dress, extending downwards from the aforementioned spider emblem. Two large "sleeves", separated entirely from the dress, are worn on her arms, ending just after her elbows. Each of these "sleeves" also display four protrusions, appearing at the ends of the significant amount of overhanging fabric. She also wears two spider earrings that hang downwards from her ears.
Arachne often carries a rather large black folding fan that is garnished with a spider web pattern.
Immense Magic Power: Despite having little physical attacks & Soul Wavelength size, Arachne has displayed mastery in her power, able to split her soul into pieces, a feat only those with advanced skill and understanding can do. Despite also having a smaller wavelength than Medusa, Medusa opted out to having Maka battle Arachne instead of her, as her magic mind attack have been shown to overpower her.
- Disembodiment Form': In this form, Arachne gains the ability to turn into "Mist-like" Madness and is able to reform into her normal appearance. Her powers are also amplified, able to not create webs almost at will, her mind attacks become potent enough to take out Medusa and cause difficulty to Shibusen soldiers, that included Mira Nygus, Sid Barrett, Black Star, and Tsubaki. She also gains the ability to cause more physical harm then she was able to in her Human form.
- Insanity Wavelength: Arachne is able to release an insanity wavelength after gaining her disembodiment form. When in use, it's very similar to Asura's Insanity Wavelength. Even Shibusen instructors like Sid Barett and Mira Nygus have a hard time overpowering it with their will.
- Master Tactician: Arachne has been shown to be great at formulating plans. She's the only character in the series to have attempted to end Death's life personally. She also patiently waited 800 Years to put her plans into action. Even without BREW, she orchestrated a plan to gain the upper-hand on Shibusen prior to the surprise attack on Baba Yaga led by Medusa. She even hid BREW from Shinigami for centuries.
- Leadership: She is arguably one of the series's best leader, rivaled only by Shinigami himself. Like Shinigami, her organization has been shown to be deeply devouted to her cause in a manner like those devouted to Shibusen, almost blindly. This is greatly seen by Mosquito, her steward, and Giriko, a loyal servant who even went out for revenge after her and Arachnophobia's demise at the hands of Maka and Soul.
- Intimidation: Despite her appearance, she is a sinister and cunning individual, much like her sister Medusa. Many witches aren't trustowrthy of her due to her being labeled a heretic. Even Mosquito, a powerful Monster in his own right, fears displeasing her and Giriko, a known loudmouth, rude, and powerful weapon speaks in a different tone whenever he does something that displeases her and she says so. Like Medusa,despite her demeanor, she holds total disregard in most life of others overall and only shows some sort of regard to the likes of those who are devoured to her such as Giriko, Mosquito, and Asura(Anime). Her disregard go to extremes such as attempting to end the life of Shinigami himself, betraying Eibon, & killing those of her own kind.
- Mind Manipulation: Arachne is extremely skilled in using her magic to Manipulate the mind of others. She's so proficient at her skill she was able to rid of the Imagination of a Great Old One. She also quickly dispatched Medusa after gaining her disembodiment in the manga.
- High Intellect: Like her sisters, she displays high intelligence. It is because of her contributions that Eibon's most powerful and arguably most dangerous Demon tool, BREW, was created. She also seems to aware of how BREW itself work.
- Skilled Combatant: Despite preferring to take down her enemies from afar, she isn't defenseless. She was able to block an attack from an enraged Crona using Ragranok with her fan with relative ease and slapped him/her, commenting about how she has aged, inferring she posses skills in Close Combat.
- Tracking Spiders: Arachne has the ability to place magic spiders that emit from her body in strategic locations and monitor the area. They function in a manner similar to a surveillance camera.
- Thread: Arachne can create threads that leave a person immobilized for an unknown amount of time - possibly depending on how strong the subject is. In her disembodied form, it appears that she is able to produce massive quantities of these threads and launch them at her opponent. However, it is not seen whether or not they have the same effect, as Maka was protected by her Black Blood dress.
In Soul EaterEdit
Arachne is known as the mother of all Demon Weapons. Following instructions found within the Book of Eibon, Arachne created a Demon Weapon by combining the shape-shifting powers of a witch, a normal human, and an inanimate weapon. This was, of course, done after killing the witch and the human first. After this, she is hunted down by not only her fellow Witches, but soon by Shinigami himself.
During her battle with Shinigami, Medusa, her own sister, betrayed Arachne and left her to perish. She ultimately broke her soul down to small spiders which, 800 years later, recollected and formed back into Arachne. In the period between these two events, these numerous spiders spread out throughout the entire world, gathering information in preparation for Arachne's return.
Arachne emerges as the spiders she had separated herself into and spread across the lands convene and congregate into her; Arachne's apparition and wavelength serves to remind Crona of Medusa. Giriko decides to explain the situation, though she needs none, as she had watched the entire world for 800 years by scattering her spiders. She knows all about Soul and Maka and about Medusa's child, Crona. Arachne makes a sharp diatribe regarding Crona's need for love. This insult would only elicit anger which galvanizes Crona to attack Arachne. Arachne easily blocks the attack and serves a well-handed hit to Crona's face with her folding fan. She then orders Giriko to erase Crona. Giriko is soon interrupted by Justin, who now battles against him. After a while of fighting, Arachne grows tired and proposes that they withdraw. Angered that he was unable to finish his battle against Justin, Giriko bitterly carries Arachne off.
During their next scene, Arachne and Giriko are walking on a red carpet, with Mosquito patiently awaiting Arachne beside their limousine to drive to her castle. Once there, she is greeted by countless followers. She then proclaims "I've won, Shinigami."
Eventually, the witch Arachne forced Mifune to protect her and Arachnophobia.
Arachne was disappointed in Mosquito for the destruction for the Moral Manipulation Machine.
Arachne meets Medusa again.
Arachne was in the flashback at the battlefield of the Temple.
Arachne has Mosquito get Kim and her weapon partner.
Operation: Capture Baba Yaga's CastleEdit
After Arachne's resurrection due to Asura's madness, Arachne heads to her massive Organization "Arachnophobia" and begins her "Magic Training"
Arachne is later discovered by Maka, Soul, and Medusa and presumed dead for unknown reasons - it is suggested that she was killed by Noah under her own orders. Shortly after this though, Maka detects the presence of Arachne within the same room containing her dead body. Soon, Arachne makes her presence known as an entity of madness and no longer bound by her body, in the hope of allying herself with Asura (though only to gain his power as her own, of course). As such, she had grown even more powerful, that not even Medusa could stand against her for more than an instant. Maka, however, manages to resist her mental attack, which Arachne notes is due to her Soul Perception and anti-demon wavelength.
As the two fought, Soul, in his spirit room, is confronted by the Little Ogre once more, urging him to call upon the black blood to help Maka. However Soul points out that doing so will only push them into madness faster and shows the imp Arachne's spider threads over the room which she is using to attack everyone within the castle. However he devises a way use them by using his Soul Resonance through them via his piano playing to counter Arachne's power, the plan works allowing Maka to hurt Arachne's disembodied form. Eventually Arachne is knocked down as Maka standing over her with an evolved Witch Hunt, citing she will take Arachne's soul.
Arachne refuses to give in however and continues the fight, but the black blood (designed as a dress) on Maka is too resilient and Arachne finds she used up too much power in her previous attacks. Just as Maka is about to give the final blow, Arachne blames her loss on her lack of power. Maka, however, counters that she just is simply stronger than her (something Medusa had noticed as she watched the fight) before striking her down and reducing her into a soul which Soul takes for himself.
However after Arachne is defeated, Medusa takes her discarded body as her own, revealing that the entire raid was a plot from the beginning to do so and she was using Shibusen as a means to an end. Before she can kill Maka (citing that her soul perception was too dangerous to witches), the death scythe Tezca Tlipoca and his meister Enrique stop her. Medusa then flees after Tezca mentions that Shibusen are about to storm the castle and when a spider web came from Medusa's eyes, which could imply the possibility of her revival through her sister.
Later on, after Maka and Soul manage to gather their 99th soul, Soul is given Arachne's soul as the primary witch's soul to become a Death Scythe.
Giriko's reaction appears to be happy as he thinks Arachne still lives and is possibly pretending to be dead like Medusa.