Sigyn

Sigyn (シギュン) is character introduced in Shinyaku Toaru Majutsu no Index as a true member of GREMLIN. She is one of the members of GREMLIN sent to Baggage City for Othinus' experiment that was to take place there, and is the only one to have betrayed the organization after the prodding of the Kouga ninjas.

Etymology
Sigyn is named after of Loki. Her name means "victorious girl-friend".

Appearance
Sigyn appears a fair-skinned woman with blond hair and blue eyes. Apparently the only member of GREMLIN who prepared for Baggage City's climate, Sigyn wears a red sweater under a white coat with a hood, along with white pants and shoes. She also wears golden necklace and golden headband.

Personality
In her brief appearance, she displays an apparent knack for whining, and having lost her way in Baggage City begins complaining to Marian Slingeneyer. She also expresses her distaste for Marian modifying people into furniture.

Sigyn is later discovered to be deceitful, apparently using Útgarða-Loki's name in reference to him becoming one of Marian's furniture, in an attempt to show her loyalty to GREMLIN, though this can be presumed to be the Kouga ninja's doing. However, she is described as irresponsible, and her actions maybe her clumsily trying to cover up her already betraying GREMLIN by the time Marian contacted her. She is described as having no hesitation to betray her allies when she has a weak understanding of them.

She is described as someone who would look like an expert at debating.

Background
Her existence as a magician is disputed. Her name gave suggestions that was ambiguously magic, and as such her status as a magician is disputed. Although GREMLIN scarcely cared for this, as they were a kind of existence that would squeeze something dry once it has value.

Baggage City Arc
She may have been the "treasure" that Oumi Shuri referred to in the beginning of Academy City's invasion of Baggage City, though this is not confirmed.

Her first appearance is in voice-only, being contacted by Marian Slingeneyer after annihilating a group of HsB-07s and FIVE_Over Modelcase_"RAILGUN"s. Here, she is apparently lost, and is asked by Marian to suggest to her to find her, which is apparently her power. Afterwards, they discuss the true pupose of the Anti-Academy City Science Guardian's Natural Selector tournament, as well as Sigyn's distaste for Marian's choice of furniture. She is last referred to as their secret weapon before losing contact with Marian as she is forced to deal with Kumokawa Maria and Oumi Shuri stumbling into her resting place.

It is only revealed later after Kumokawa Maria and Oumi Shuri turn the tide on their battle with Marian that she discovers the truth. After Marian contacts Sigyn for help, she discovers that Oumi completely imitates her voice, and assumed that Sigyn have been captured by Oumi's comrades and have been forced to cooperate with them and have Sigyn trick Marian during their earlier conversation. Oumi later shows the weakness Sigyn showed to Oumi regarding Marian's power, alcohol, and made Marian's "materials" (living humans transfigured by her) drunk, and made them unable to carry out the function Marian assigned to them.

It is unknown what had befallen Sigyn afterwards.

Abilities
Her ability is that she is able to give a suggestion to someone, and the recipient of that suggestion would do it 100% accuraretly. However, Sigyn herself cannot do it for herself. It was hinted that if she did, she can even reach the realm of being a Majin.

She is referenced as being originally could not only give suggestion to her allies, but also give wrong suggestions to the enemy and cause them to self-destruct. She is also referenced at being more apt at analyzing the opponent’s logic than magic, and would add on to it.

Design evolution
Currently appearing only in a single volume, Sigyn's remains the same. Despite the ambiguous nature of her appearance in the novel's story, she was given a design to her appearance in one of the illustrations with her comrades, as well as match the Kihara trio, who all appear in their own illustrations.

Quotes

 * (To Marian from NT 4) "Your interest is unpleasant. Dissecting living people and making them into the shape of furniture? I never want to be invited to your tea party."