Gungnir

Gungnir (主神の槍(グングニル)) is the legendary weapon of Othinus (Odin).

Etymology
Gungnir in Old Norse means "swaying one", probably to signify how spears are usually wielded. It is usually represented by the Gar rune.

The kanji used for Gungnir (主神の槍), can be translated as Spear of All-Father, with All-Father (Alfaðir), one of the titles attributed to Odin.

Concept and Origin
Gungnir, as stated, is Odin's spear in Norse mythology. In the Prose Edda was fashioned by Dvergrs but was later obtained by Loki and given to Odin as reparation for cutting Sif's hair. From that point on, It would later be used by Odin in Ragnarok against Fenrir.

The Gungnir is described as having the ability to always pierce clearly through its target and as never stopping during its thrust.

Appearance
Only the replica of the spear has been seen, from the Toaru Majutsu no Index SS: Norse Mythology. There, it looked like a large 3 meter ash tree branch, with many pieces of steel that intertwined around it, and have the characteristics of several other weapons other than the spear, such as the sword and of the ax. It's appearance deceives the eye, a kind of trompe-l'œil. It pulsates like a living being, like a snake wrapped around a tree branch.

However, in Toaru Majutsu no Index: New Testament 8, it's design was different. It's a golden spear with pieces of intertwining steel at the end of the handle and below the blade. It's broad blade also have design that somewhat looks like a branch with leaves on it.

Toaru Majutsu no Index: Norse Mythology

 * Main article: Toaru Majutsu no Index: Kanzaki SS

A prologue of sorts, it is first mentioned by Brunhild Eiktobel in "To Aru Majutsu no Index: Norse Mythology" as her goal of creating a Gungnir by using a replica of it to carve the final rune into the core of the planet giving her the power to save Ceillier Flatley, who attempted to committed suicide because of all the guilt he felt after failing to save her from being repeatedly tortured. When wielding the replica she was only able to draw out 70% of it's full power due to the lacking of the finale rune, yet was still able to create natural disasters like Lightning, Tornados, Volcanic Eruptions, Floods, Earthquakes with ease. Due to her being a Saint as well as a Valkyrie she would at times subconsciously start creating the magical symbols for the Christian Lance of Longinus are mixed in, this would lead to her defeat by Kanzaki Kaori, using the symbolism of the Christian cross against a Saint like Brunhild, which was a weakness to them.

Hawaii Invasion Arc

 * Main article:Hawaii Invasion Arc

It is next mentioned in the epilogue of the 3rd Shinyaku Toaru Majutsu no Index Light Novel, after the failed invasion of Hawaii by Marian Slingeneyer, a Dvergr of GREMLIN to another member called Odin (One-Eyed Othinus) were they were planing to use Brunhild Eiktobel to attain Gungnir for their plans.

Lance of Gungnir Arc
GREMLIN started its production after preparing everything and creating a hollistic esper out of the Dark Matter produced by Kakine Teitoku. Once that everything were in place, the production started. The process is essentially a magic ceremony but cannot be completed solely with magic since the automatic work will stall somewhere. To accurately throw in the holistic esper and continue the ceremony with the proper timing, it needs to be switched over manually.

It turns out that in the end, the production of the spear failed, but Othinus happened to create a back-up by herself hidden within her body. By having the Gungnir and the fairy spell by Ollerus and Fiamma, she then both have the solutions to get rid of her 50/50 restriction. She then pulled it out from her eye socket in which Kamijou was dumbfounded. She then raised its tip to the heavens and declared that she will just end the world.

Abilities
It is Odin’s spear in Norse mythology. The weapon of the gods signifies in Norse mythology the power of that god itself. The gods could wield their power because they possessed their weapons. There were stories of gods temporarily losing their powers due to losing their weapon or having it stolen. Meaning someone wielding Gungnir wields the power of Odin and could draw out the spear’s true power and would be able to freely use the great power that made Odin a god.

As a weapon of one of the chief gods of Norse Mythology, it is extremely powerful. The replica alone, even with only 70% of its power was enough to overwhelm Kaori. Simply existing, the spear threatened the balance between the magic and the science side.

The spear is said to be able to destroy the legendary weapon Balmung, and any other weapon. It is said to be able to hit any target when thrown, said to be unblockable, and would return to Odin once thrown. However, Brunhild, stated that is something added only by people in legends, and it's true power is that to control the weather and other natural occurences. At that point Brunhild showed Kaori, the power of her Gungnir replica, controlling thunder, magma, water and even salt to damage their battleground, however, it may have been due to the corruption of it by Christian elements.

Wielding the Gungnir rids the magic god Othinus of her 50/50 restriction by giving her 100% success.