"The power of the Kishin goes beyond human understanding. It is evolution itself! Shinigami and you at DWMA have watched over and protected the world by acting as a deterrent to that power. DWMA's intent can be summed up in one expression: "Maintain the Status Quo." But time moves forward. Isn't it logical that we grow and advance along with it. It's only natural. Doctor Stein...do you really want a monotonous world...where nothing ever changes?"
Medusa Gorgon (メデューサ・ゴーゴン, Medyūsa Gōgon) was the sinister witch who is the mother of Crona and manipulates Crona into collecting innocent human soul they come across in an attempt to make her child a Kishin after replacing the blood of her child with Black Blood, in which Ragnarok was melted in. She was also later responsible for the revival of the Kishin, Asura. She is the first antagonist in Soul Eater.
Medusa was one of the Gorgon Sisters, being the second born. Eight hundred years ago, she assissted Arachne in her fight with Death. However, she later betrayed her and left her for dead. Since then, she began creating "Black Blood ". Centuries later, she had a child she named Crona. She then melted a demon weapon known as Ragnarok with the black blood and replaced Crona's own blood with Black Blood. Since then, she gained an interest in harnessing Madness. She decided to pose as a nurse at Shibusen to learn where the Kishin was sealed.
Medusa is an incredibly sinister and evil individual, as well as a very powerful witch. Her greatest skill is her ability to manipulate almost anyone, due to her unbelievably high skills in acting. In her true personality, Medusa has a view of the entire world as a place of stasis, where nothing evolves or changes. She hates this so much that she went to the extent of resurrecting Kishin Asura in order to make the world mold back into "motion". She also takes incredible pleasure in others' pain when she is the one causing it, and when her experiments are working. She is so sinister that she can even subject her own child, Crona, to unimaginably torturous punishments, like locking him/her in a dark room for many days without food or water whenever he/she fails to do what she commands them to do, and gives him/her terrifying orders such as to devour many human souls.
She is easily angered by those who create a road block in her experiments or in the "evolution" of the world, and usually tries to eliminate these problems.
Although she seems so dark, to say that Medusa has no love in her is a false statement. Deep within Medusa is her own, unique, sinister form of love that comes out extremely rarely. She expresses romantic love specifically towards her confirmed crush, Dr. Stein, whom she finds attractive because of his inner darkness. She also has a motherly love towards Crona, which only comes out after Crona has become a fearsome killer and spreader of Madness. Uniquely, in both cases, Medusa had openly stated that she loved the person right before the same person kills her.
However, in the anime, Stein states the little love Medusa has in her is only a hoax. He calls her out on this in his first battle with her, stating "At your core, Medusa, you're just like me. You could never understand a concept like love." Based on her evil and manipulative actions, this could very well be true.
Despite this, Medusa is primarily proven to be the most evil individual in the series, even more than Asura. In the anime, Maka's Majin Hunt technique, a technique based on erasing all evil, is the only thing able to kill her for the reason that she is pure evil. In contrary, when Maka utilizes the kishin hunter (A more powerful variant) against Asura, it is unable to kill Asura because he is actually the embodiment of madness, which is not completely evil.
Medusa is a woman with a fairly average physical build, and a large, black, dotted snake tattoo winding down either arm. Her facial features consist of eyes containing yellow irises with black pupils, and blonde hair arranged in a spiked style, with two long strands extending downwards framing either side of her face, that entwine each other like a caduceus' snake to rest upon her chest. While she wears many outfits over the course of the series, the most notable and common of these is a black body-length suit with hood, which extends downwards to her knees. The hood itself is adorned with an eye-like marking upon either side which, interestingly, when worn in addition to the shape of her hair, gives it the appearance of a snake's mouth, with teeth and fangs. Medusa also has a tail which is shaped like an arrow. It is notable that she is always barefoot, when not in disguise, with unique toenail and fingernail polish that is black featuring yellow arrows pointing upwards. On an interesting note, she is often introduced feet first throughout the series.
Medusa's witch animal theme is snakes. She uses the magic chant "Snake snake cobra cobubra", and is themed with arrow markings. Also when she gets serious or just wants to be scary, her face takes on the likeness of a snake.
Her soul also takes a snake-like theme, closely resembling the head of the Gorgon of Greek Legend, Medusa. However, instead of snakes it has the same vector arrows that are present within Medusa's spells and features a purple color.
After the revival of the Kishin Asura and her defeat by Stein and Spirit, she was forced to take possession of the young child's body. This gave her the same build and frame of the child, while still retaining the majority of her original form's appearance. However, the body did have some practicalities, as she found it particularly useful in deceiving many people. Medusa still attires herself with the usual hoodie but this one has two snakes like extensions that are attached at the neck. There is also an apparent white snake head motif on its front. Also, rather than a bodysuit, Medusa sports a knee-length dress, and unlike her adult form, does not wear nail polish. Perhaps the most noticeable change in Medusa's appearance is the absence of the snake tattoos on her arms.
Seeing the opportunity after Arachne's defeat by Maka during the capture of Baba Yaga's Castle, Medusa leaves her previous victim and transfers herself to the empty shell of Arachne's body. This current possession shifts Medusa's appearance much closer to her original form but now bearing Arachne's black hair color arranged in Medusa's typical style. She chooses to also adopt her typical long hoodie preceding the transformation, with it now featuring an indistinct spider's web patterning surrounding the neck line.
Medusa also has a nick on her left eyebrow originally. However, the nick vanishes when she possesses Rachel and Arachne.
- Medusa's name is an reference to Greek mythology's, Medusa, who was one of three Gorgons, just as Medusa is one of the three Gorgon sisters in the series. She also happens to be the only one revealed so far to have the same name as one of the actual Gorgon sisters, as Arachne is named after a woman who turned into a spider by Athena in Greek Mythology.
- Medusa's Vector theme appears to be based on Shotaro's "Bones of Medusa"'s ability to fire vectors/snakes like Medusa's vectors from Atsushi's earlier series B. Ichi.
- In the "Atsushi Bar" postface of volume 4, it is revealed that Medusa's braid is curling to the right when she is as a witch and curling to the left when she is as a nurse. However, the first time she appears as a witch, her braid is mistakenly curling to the left.
- In Episode 40 of the anime, it is seen that on her prison door, her name is misspelled as "Witch Medousa".