Einherjar

Einherjar refers to the resurrected people used by Othinus and her GREMLIN.

Etymology
The term derives from the beings of Norse Mythology, the, which means "lone fighters in" in Old Norse. The einherjar are those warriors that have died in battle and are brought to Valhalla by valkyries. There, the fight all day and eat and drink all night. The einherjar are constantly preparing, where they will fight on the side of Odin.

Principles
Not much is known on how a dead person can become an Einherjar, though what is known is that it requires gold, and that it is inserted into important parts of the human body, and with that the corpse can be controlled without it decomposing. According to Othinus, only humans can be turned to Einherjars, as such those persons who have touched the realm of a god, like that of Ollerus and Othinus herself, both have properties of a magic god or Magic God cannot be turned to Einherjars. Most likely, a person who has been "turned" into a fairy cannot be turned as well.

Einherjars survive through being "poured" by magic power from an external source. From there, the body keeps on beating and their brains keep on producing thoughts. Apparently after fulfilling a command it would request another one to do.

According to Touma's analysis, it is likely Othinus "perfected" the Einherjar spell through the Lance of Gungnir in order to make the "perfect world", where the various tragedies and trauma's that have come to pass in Touma's world have not happened, and those who have died are alive and well.

Appearance and characteristics
The appearance of an Einherjar remains relatively the same, as well as their scent and feel of the skin, and apparently do not speak needlessly. They are able to move about, and can apparently be controlled by Othinus through commands like a normal human.

As exhibited by Kihara Kagun, an Einherjar can still use all their abilities and skills that they have when they were still alive. As such, they can still use their magic or their knowledge remains the same. They are also able to work day and night tirelessly.

In Kihara Kagun's case, due to the nature of his death, he does not breathe, cannot feel, nor show any signs of the normal reflexes and reactions of a living creature. As an Einherjar he is essentially an emotionless object that carries out precise movements. It is unknown what other features other Einherjars would have.

Baggage City Arc
After Kihara Kagun's (Bersi's) death, Othinus turns him into Einherjar, promptly trampling on his efforts to kill himself at the same time as his nemesis. Othinus then has Kagun carry the unconscious Marian Slingeneyer after she leaves Baggage City. Here, when she comes to, she recognizes Bersi's scent and feel of his skin, though after she talks to him, she realizes that he has become an Einherjar. It is implied during her conversation with Othinus, that they are now many Einherjars, and that Kagun is now part of its ranks. Apparently, there are enough of them to referred to as an army of the dead.

Magic God Othinus Arc
As he is a valuable asset in the production of Gungnir, Einherjar Kihara Kagun, also known as Bersi, is used by Othinus to create a parallel processor made up of the scraps on Sargasso parked in the waters near Tokyo. After fulfilling his duty, he is sent out by Othinus to eliminate his enemies after he asks, which he obliges. However, Kagun, in his preparedness to take down Kihara Byouri, inserted a semiconductor into the back of his neck which would activate when he does something that he would normally not do. It is because of this that he is able to save Kamijou Touma and the others from an attacking Níðhöggr summoned by Freyja.

Kumokawa Maria who intended to find him through Kamijou Touma and his dealings with GREMLIN later walks by his side as she carries the unconscious body of the woman who was once known as Freyja. She does this in spite of knowing that he is dead and that he is being controlled, wanting to witness his final actions and to later give him a proper burial in Academy City.

Known Einherjar

 * Bersi