Fenrir

Fenrir is a member of GREMLIN the is introduced in as being a member in their world wide assault.

Etymology
In Norse mythology, is a monstrous wolf. Fenrir is the father of the wolves Sköll and Hati Hróðvitnisson, is a son of Loki, and is foretold to kill the god Odin during the events of Ragnarök, but will in turn be killed by Odin's son Víðarr.

Appearance
He was only described as being a young man.

Shinyaku Toaru Majutsu no Index
He appears in Alaska to take out a NORAD base their as a means of sealing off their intelligence network. When he reaches where the bases parabolic antennae arrays are stored he is ambushed by Oriana Thomson, to with he effortlessly blocked. After the explain of his distortion spell she commented that she would just have to use the countermeasures she developed if she should have to fight Kamijou Touma again. Realizing shes comparing his power to the Imagine Breaker he retorts that he doesn't completely annihilate the occult and can not take the role of being a reference point for the world.

Abilities
Fenrir is able to distort the world around him using Idol Theory. Taking the story of how the gods had feared him because of how he would devour Odin during the final battle of Ragnarök, and so they bound him and stabbed a sword into his mouth through the lower jaw so he could not close his mouth. When they had, the drool that had flowed from Fenrir’s giant maw had created a large river. Using something similar to feng shui where the existence of mountains and rivers changes the flow of energy through ley lines and the like. In this case he can create a ‘ditch’ that draws in the surrounding energy by creating a new mountain or river. The spell creates a number of black cracks forcibly swallows up the magic power that constructed magic and swept it away. He also states that he

Another comment of his hints at simply being able to Oriana apart with his teeth.