Othinus

Othinus (オティヌス(オーディン)) is a character introduced in Shinyaku Toaru Majutsu no Index. She is the current Magic God and is a true member of GREMLIN, and its leader.

Etymology
Her name, Othinus, is the Latin name for Odin, the Norse god of war, wisdom, magic and poetry, among other things, which is also the alternative reading of her name.

Appearance
She is referred to as One-Eyed Othinus and, similarly to the Othinus of legend, she wears an eyepatch over her right eye which she has presumably lost in order for her to drink from the Well of Wisdom, though this may just be a ritualistic and aesthetic choice, as Othinus is maybe invoking Idol Theory to match that of Odin of Norse mythology.

She's seen dressed in a fur coat and a black leather oufit. She also wears a wide brimmed hat with a pointed tip, one which would have been worn by a witch.

Background
The first implication of Othinus' existence in the series is when Ollerus uses the queer magic, Hliðskjálf, upon Sogiita Gunha. This magic, of course, is named after the high seat of Odin, which allows him to see into all realms. In the Gesta Danorum, Odin was exiled and Ollerus was chosen to take his place. This can be presumed why Ollerus currently has the Hliðskjálf.

Othinus would later attain the legendary title of Majin from Ollerus, which Ollerus proclaims to have been stolen from him, making her one of the most powerful beings in the Toaru Majutsu no Index storyline. This would mean that the girl that currently holds the title, has named herself as Othinus for a long time before even the creation of GREMLIN.

World War III

 * Main article:World War III

Othinus is mentioned in passing by Ollerus after finding Fiamma of the Right, referring to her as the person who stole his title of Majin.

Hawaii Invasion Arc

 * Main article:Hawaii Invasion Arc

She appears in voice-only, talking to Marian Slingeneyer the Dvergr, over the phone, regarding their plans, and their successful fulfilment of one its steps, the eruption of Kilaeua and the spreading of volcanic ash upon the world, and states on how she has gotten a report regarding Brunhild Eiktobel the Valkyrie, who once used Gungnir, a portion of it however. Their conversation is interrupted by the arrival of the Cendrillon, who is quickly defeated.

Baggage City Arc

 * Main article:Baggage City Arc

With Bersi's knowledge in the darkness of Academy City, she allows him to be the only to know the true extent of the distortion that would occur for the experiment in Baggage City and orders him to adjust the experiment depending on the scope of what Academy City's forces that would inevitably attack. After Bersi's death, Marian Slingeneyer swears to avenge him and prepares to unsheath Dáinsleif, the harbinger of Ragnarok. Othinus calls the Dvergr and beseeches her not to do it, or she would ruin GREMLIN's experiments. Marian merely scoffs at her.

When Kamijou Touma defeats Marian Slingeneyer and prepares to destroy Dáinsleif for fear it could be mastered and used at its full potential, Othinus reveals herself, stopping Touma and severing his right arm and crushing it.

Othinus promptly destroys Dáinsleif with her powers, cursing how Marian had to create such a thing. But then, the Invisible Thing within Touma tried to break free, though Ohinus used her powers to suppress it, seemingly unimpressed with its state and form. It is then that Ollerus appears to confront Othinus, suggesting she leaves with Marian as he has business with the Imagine Breaker. The two spar and browbeat each other until Ollerus reveals he has Fiamma of the Right on his side, empowered by the fact that Kamijou Touma's arm was severed, allowing his world-saving powers to activate. Seeing this, Othinus begins to carry off Marian, but decides on a whim to fight and kill them off. The match ended in a draw.

Later, Othinus used her powers to raise the dead Bersi from the dead to join the Einherjar and carry Marian for her. There, she declares the pieces are coming together. Having acquired a proper furnace in Hawaii and Gungir's blueprints having been stolen, all that's' needed is a specimen to become a Holistic esper — someone greater than a human, without Valkyrie or Saint properties that hasn't been altered by Academy City's Power Curriculum Program. Such a specimen exists within the confines of the Windowless Building.

Abilities
Othinus is a Majin, which makes her a perfect and pure magician that encompasses every possibility. Because of this, since it is every possibility, she has an equal chance at succeeding and failing, making her magic a 50/50 shot. The reason she seeks to craft and wield Gungnir is to control the probabilities of her success and failure, effectively ridding herself of 50/50 restriction.

Despite this, if she is successful in using her powers, she has shown to be extremely powerful. She was able to crush Touma's right hand as well as the invisible thing that came forth to attack her with strange ease.

Furthermore, as a god, she has territory over the dead, which allows her to turn Bersi into an Einherjar, though the process is unknown.

Quotes

 * (To Kumokawa Maria from NT4) "Unlike a certain failure, I am a pure magic god. If that is not enough for you to understand, my words are wasted on you. You should just give up on understanding."