Loki

Loki is a member of GREMLIN the is introduced in the beginning of the assault on Sargasso.

Etymology
In Norse mythology,, is a God or  (or both) and is the companion of Thor. Loki's relation with the gods varies by source. Loki sometimes assists the gods and sometimes causes problems for them. Loki is a shape shifter and in separate incidents he appears in the form of a salmon, mare, seal, a fly, and possibly an elderly woman. He should not be confused with Útgarða-Loki who is named for the a different, his name literally means "Loki of the Outyards" to distinguish him from Loki.

Appearance
He was described as an old soldier holding a cane and wearing a silk hat and tailcoat that look like an illusionist or a stage performer.

Shinyaku Toaru Majutsu no Index
He appearers before the Knight Leader, William Orwell and second princess Carrisa after the initial bomb bombardment of Sargasso and introduces himself to them. He comments that Othinus gave him the task of protecting this place with his life before his explanation is cut short by being shot with an arrow fired via a Robin Hood spell. Loki then fell from the tip of the tanker he was standing on and slammed into the ground Carrisa then ordered all of them to continue moving foreword.

Abilities
Loki is an illusion specialist of GREMLIN

Víðópnir (Old Norse, possibly "wide-open" or "wind-weaver") is a rooster that sits at the top of Mímameiðr, a tree often taken to be identical or another name for the World Tree Yggdrasil.
 * Territory of Víðópnir: