Nephthys

Nephthys (ネフティス) is a "bizarre magician", a magic god, who dwells in a territory beyond a certain layer of the world.

Etymology
is a goddess in Egyptian mythology associated with death and, together with, a protector of mummies. She was said to have shed large tears upon the death of Osiris, but no other stories are known about her. For that reason, it is speculated her divinity had been based on the “” hired to attend funerals.

Appearance
Nephthys is a beautiful woman with chocolate-brown skin and long silver hair. Her eyes can apparently change color at a whim and she has teardrop and diamond markings below her eyelids. She doesn't wear anything except the white bandages covering her body. Several of the bandages have pyramid-shaped decorations attached at the ends.

Personality
Nephthys is apparently quick to judge, willing to interfere with the normal world and look down upon Othinus despite her being a magic god herself.

Although Nephthys tends to look down on humans, she does claim to like and be jealous of the passions and movements of the human heart, giving humanity's dream and efforts towards reaching the stars as an example.

Nephthys is a goddess who objects to legends of death which are treated as necessary sacrifices in Egyptian mythology, once weeping and reducing an entire magical faction to ash as they were about to ritually sacrifice a girl in an experiment to prove heaven existed. With her origins as the "crying woman", Nephthys is susceptible to being moved to tears and crying with someone, even from watching an awful drama for less than a minute.

Background
Nephthys's background and origins are largely unclear, as stories and materials concerning her are extremely rare, other than the story of the "weeping goddess" at Osiris's funeral. Even with that story, and one theory that she was artificially created to emphasize it, no one knows anymore if it was truly Nephthys, not even Nephthys herself. However, her divinity is said to have originated from the "crying woman" paid to attend funerals in ancient Egypt, in this case in particular, the thousands of servants buried alive in a pyramid for a pharaoh's burial,  to ensure the king had no trouble in the afterlife. For these buried servants, the end often took its time coming.

In one particular pyramid, in an unknown time and place, as the buried servants were waiting for the end, someone thought that they didn't want their life to have been wasted, and together with the hundreds or thousands of others, collected the pieces of knowledge they had and the papyrus materials buried with the pharaoh for his resurrection together. After it was gathered together, Nephthys was born, surrounded by countless corpses - whether they were the original form which created her or the shell of the egg, not even she knew for sure.

At some point, Nephthys appeared to a man who was weeping at his faction's imminent ritual sacrifice of a girl in an experiment to prove the existence of heaven and his inability to say it was wrong, wishing for someone to stand with him as he lamented. Nephthys told him that his voice had reached her and that she'd also weep with him. Immediately afterwards, she gave a shrill cry that reduced the magical faction to ash in an instant.

At another time, Nephthys observed as Aleister Crowley entered Egypt, like many other European magicians who had reached a dead end and sought out new material to make a breakthrough, and laughed as he incorporated the names of Isis, Osiris and Horus into his concept of Aeons.Shinyaku Toaru Majutsu no Index Light Novel Volume 14 Between the Lines 3

Magic God Othinus Arc
In that world where distance and time doesn't matter, Nephthys first appears after the events of the arc has occurred, with Kamijou Touma saving Othinus and her turning to a depowered 15 centimeter Magic God. The being asks the High Priest, if they should interfere now. The High Priest explains that the events that have transpired might hinder Touma's development, though says that he doubts that anyone but them can resolve it now that a magic god is in involved. Nephthys asks for confirmation if they are influencing events by interfering with the existing world, to which the High Priest says that the High Priest isn’t so foolish that he wouldn’t calculate all it out. He then says that it just goes to show to them how different an existence Othinus was, though he doubts that she realizes the truth behind GREMLIN.

Nephthys says that Othinus was a failure, to which the High Priest replies that she reached the level of a magic god and as such Nephthys need not be so cruel when referring to Othinus. Nephthys says that the High Priest is as kind as ever when it comes to judging other, and says that if it didn't come from looking down everyone he might've achieved enlightenment. High Priest then says to Nephthys that they are all lacking in some way, and says Othinus was the same though she went a bit too far, though says that is just the kind of person GREMLIN gathers.

Niang-Niang then appears saying that GREMLIN isn't a fusion of magic and science but an organization that every magic god of every religion can take part in equally. She is questioned to where she has been, to which she says that the concepts of distance and time doesn't matter in this place, as they already know. She says that she can't leave regardless, and even if she did, she'll just garner unwanted attention on a global scale like Othinus. The High Priest magic god asks if it is the same for the others, to which Niang-Niang asks if he has started forgetting things once he had become a mummy. She says that the others, the zombie girl, the chimera, and everyone are here in this layer of the world. Niang-Niang says that it is destiny’s hand that allows them run across each other in the first place in this layer of timelessness and infinite distance.

One of them says that being stuck in there is one way of being ecological. They are there because the world is too small for them to live in, though laments that it isn’t being there. Niang-Niang then says that is just the exact reason why she is mad at Othinus, because was so selfish. One of them then says that the strength of the world was enough to withstand everything she did, and says what Othinus has done will not have any real effect on the situation.

Nephthys then asks if the can continue as planned. The High Priest replies that they can as the High Priest had just corrected the disorder caused by Othinus, and says that now, GREMLIN will show its true value.

Suddenly, Aleister Crowley himself appears before them. Here, he comes upon "bizarre magicians" talking about what had transpired, to which he refers to as "GREMLIN". One of these magicians references his absence as of late, though states that Alesiter may have been busy with a side job. Aleister says that he had to let the strength of the world handle Othinus running around free as he had something to prioritize in entering their "divine territory" as it wasn't easy. One of the magicians, referred to as "someone" with a hoarse voice, comments on how if Aleister turned his obsession in destroying magic in the right direction then he too would be part of GREMLIN. Aleister says that he made adjustments to himself that it would not happen, as such he can control something different than them who can only live in a distorted phase. The magician with the hoarse voice asks if science is really wonderful enough for Aleister to indulge himself to that extent. Aleister then comments on how even if took them an eternity, none of them would understand. The magician with the hoarse voice then asks if it has nothing to do with "the single remaining tear stain in his journal".

Aleister is silenced by this, and all remaining expression on his faced vanished as he calls upon his magic name Beast666 and draws out his magic staff. The magician are unperturbed, one of them comments on how is envious of his emotion, though says he should stick around as he says he is about to tie it all together. He tells him that Aiwass, the cornerstone of his plan that he tried so hard to raise is a complete failure and that Aleister will be at his wit's end before long. A moment later, Aleister attacks them.

The battle with the magic gods leaves Aleister's body terribly damaged. However, the attack was all but a ruse to allow Aleister to kill them, switching the spell that Zombie (another magic god) had, which would allow magic gods to go to the world of humans without affecting it by the sheer power of their existences.

St. Germain Arc
With their Hidden World lost, the High Priest, Nephthys, and Niang-Niang descend into the human world after using Zombie's spell, unaware that Aleister has already played his hand. They arrive just in time as St. Germain begins his antics in the Dianoid. Despite really wanting to interfere, especially since Kamijou Touma is in the the Dianoid as well, they are unable to do so as they are still too powerful to do so and would've likely destroyed the world in the process. Much of their actions is just walking around Academy City and observing the events that are unfolding with regards to St. Germain.

After St. Germain's defeat they are ready to interfere with Touma's development. However their plans come to a standstill when Aleister Crowley communicates with them. They once again mock him but they are suddenly skewered by stakes through their chests. Shocked that they could be harmed, Aleister Crowley reveals that he had swapped the spell Zombie used to allow them to be in the world without destroying it with his own, allowing them to be vulnerable to him, and declares that he no longer considers them a threat. At that moment, Kihara Noukan catapults the body of Zombie, crucified on a steel cross and wrapped with barbwire, into their midst.

Magic God Invasion Arc
During the High Priest's rampage through Academy City in pursuit of Kamijou Touma, Nephthys and Niang-Niang approached Touma as he and Misaka Mikoto temporarily stopped on a workship. After testing to see if Imagine Breaker could return them to their full power, without success, the two offer their assistance to help stop the rampaging High Priest. Though Touma rejects their direct involvement, he and Mikoto reluctantly accept their offer of advice and the two Magic Gods give Touma an explanation regarding the nature of the High Priest before leaving.

After the Arrowhead Comet's destruction and the High Priest's death, Nephthys reluctantly allows Niang-Niang to wipe out the city to eliminate the threat to them. She is then shocked when Niang-Niang is devoured and 'exiled' by Kamisato Kakeru's World Rejecter. After learning about the World Rejecter and how the other Magic Gods have fallen victim to it, Nephthys recognizes the threat and attempts to embed a phase to stop him, but fails and falls victim to it herself. Escaping through her separated organs, Nephthys makes contact with Kamijou Touma and requests that they work together, saying that if Kamisato Kakeru was exiling the Magic Gods then Othinus would also be in danger.

Abilities
Being a Magic God, Nephthys is powerful enough to risk destroying the world with her mere presence unless precautionary measures are taken. Even weakened by Aleister's spell, Nephthys is still capable of destroying the world and shifting the phases once.

Due to her divinity originating from the crying woman from funerals - in particular the thousands of servants for a pharaoh's burial, Nephthys differs from other Magic Gods in that while others thoroughly honed their powers as an individual, she specializes her power as something which can be separated, split apart, cut away and swapped out.

Due to her secondary organs being separate from her main body, Nephthys is capable of making use of them to escape if something happens to her main body, such as being 'exiled' by World Rejecter.

Nephthys is also able to emit a shrill cry which causes matter to vibrate intensely, capable of instantly turning an entire magical faction to ash.

Character Art Design
Haimura designed Nephthys as he was told, giving her no real motif and only adding her changing eye colour. He later made her outfit less revealing and added green markings below her eyes in his final design for her.

Quote

 * (To the High Priest, from NT10): "Othinus was a failure."
 * (To Touma and Mikoto, from NT13): "The stars can be plucked from the sky so easily, but you humans feel such passion for such unimportant things."