Norse Mythology

Norse Mythology (北欧神話) is the mythology of the North Germanic people around the time of the (at its height covering most of northern Europe, much of modern Germany and Austria, and parts of the British Isles), continuing through into modern-day Scandinavian folklore, and following the lives of the Norse gods — the  and the  — and the men whose lives they directly affected.

In Toaru Majutsu no Index, Norse mythology is often used as a base for Magic. Its prevalence in its usage as a basis for magic is second only to Christianity.

Etymology
It is important to note that the correct appellation is Norse Mythology, not Viking Mythology. Originally, the word "viking" meant the act of faring overseas and the sailor participating, while in English it denotes a profession meaning something like "pirate". Only a minority of Norsemen were Vikings.

Principles
Like most traditional polytheistic systems, it has no set canon and in some ways resembles a body of customary beliefs more than a set religion. It has been speculated that only chieftains and other wealthy people held faith in the Æsir, while the common farmers believed in land-spirits such as dwarves, trolls and giants.

It is a branch of the Proto-Indo-European mythological tradition, which also spawned the Celtic, Greek, and Vedic pantheons; its gods are not only fallible, but also all mortal. They could, and did, die, as exemplified during Ragnarok, the Norse version of the apocalypse, which ends with most of the gods dead.

Many texts describing Norse beliefs have come down to us, but, aside from a few runic inscriptions and similar fragments, all were written hundreds of years after the turn to Christianity. Consequently it's nearly impossible to tell which stories are "Christianized", or how much they are, although academic theories abound. Even ignoring this, another problem arises: since Norse myth has no definitive canon, the myths differ considerably from place to place, according to the time they were written and the purpose they were written for.

Norse Mythology being a polytheistic religion, its gods had emotions that are very much alike those of humans. When the opinions of all the many gods were gathered, it created a single flexible system. As long as that system ultimately led them down the right path, everything was fine. As the gods of Norse Mythology are not absolute, the gods reach perfect answers when combined in a single group by complementing each other's weaknesses, creating a sturdy defense system. Moreover, an intrinsic property of Norse Mythology is that it is a mythology of mutual destruction, set up from the beginning so that over 99% of gods and their enemies would die fighting each other (likely a reference to Ragnarok). As such, a magician can create a countermeasure against a spell that uses figures from Norse Mythology if they made use of the figure that killed the other figure in the mythology.

Background
It is implied that the legends surrounding Odin is derived from the Magic God Othinus herself or that Norse mythology, apparently among other religions, was influenced by her existence, such as the religion shifting from one centered around a hammer-wielding lightning god to a lance-wielding god of war, a god of magic sacrificing his own body by hanging himself from an ash tree to fulfill a contract, and Odin being a muscular one-eyed man with beard. It is implied that Othinus may have deliberately took different forms that eventually found its way into the mythology.

As a pagan religion, it is likely that Norse religion was also affected by the onslaught of Christianity and had their old gods either referred to as fairies or classified as demons.

Toaru Majutsu no Index SS2
During this collection of sidestories, Kanzaki Kaori encounters a Valkyrie known as the Jeans Slasher, and Ollerus makes his first appearance.

British Royal Family Arc
The group New Light, which made use of Norse-based magic, was involved in transporting the Curtana Original in the lead up to Carissa's coup d’etat. Moreover, the Knight Leader incorporates Norse Mythological aspects into his spiritual item Hrunting as well as a defensive spell known as Thororm's Defense Formula. A defensive spiritual item based on Mokkerkalfe at Buckingham Palace also appeared. After the Russian Orthodox Church falls into the hands of Fiamma of the Right, Vasilisa has Sasha Kreutzev escape into the snowy Russian lands. Here, she is pursued by members of Annihilatus using the Sleipnir spiritual item.

World War III Arc
While Touma and Lessar were discussing their next course of actions, they saw several Sleipnirs which Touma mistook for large military trucks until he saw the horses pulling them. Lessar then explained what the tools were and told Touma that villagers were probably being relocated to concentration camps, in order to clear the area that would be used as the staging ground for the Star of Bethlehem. When Fiamma used the remote controler for activating Index's John's Pen Mode, it made use of the Sword of Freyr against Stiyl Magnus while trying to escape the underground portion of St. George's Cathedral. Later, Othinus is mentioned in passing by Ollerus after finding Fiamma of the Right, referring to her as the person who stole his title of Magic God.

Toaru Majutsu no Index: Stiyl SS
The conflict in this sidestory was over several artifacts which were believed to have held the secrets of the Dvergr's skills. The main antagonist, Richard Brave used Magic based on the flaming sword Lævateinn.

Toaru Majutsu no Index: Kanzaki SS
During the events of this sidestory, Kanzaki Kaori fought a variety of adversaries who made use of Magic based on Norse mythology, culminating in a battle with the Valkyrie Brunhild Eiktobel who sought to complete Gungnir.

Shinyaku Toaru Majutsu no Index
The first part of Shinyaku Toaru Majutsu no Index consists of the protagonists' struggles against the Norse-based cabal GREMLIN.

Norse-based Organizations

 * GREMLIN (magic cabal, disbanded)
 * Five Great Norse Societies
 * Those Who Prevent the Extermination of the World Tree (magic cabal, destroyed)
 * Iron Stake that Carves Knowledge (magic cabal, destroyed)
 * Champions from the Sea (magic cabal, destroyed)
 * Those who Know the Rune of the God’s Sword (magic cabal, destroyed)
 * Hammer that Tempers Gold within the Earth (magic cabal, destroyed)
 * New Light (pseudo-cabal reserve army, active)