After Othinus had defected from GREMLIN and fled with Touma, the organization sought vengence after her and declared their quest for revenge in Denmark. After a long manhunt, the remaining members are hiding in Russia and remain there in order to survive after the Vasilisa of the Russian Orthodox Church and Annihilatus declares them to be killed and the organization is left dissolved at the end.
GREMLIN was founded sometime after World War III in response to the events that were started by Fiamma of the Right. They are an ideology-based organization that was formed in response to the frustration that many people and their members had felt towards Academy City and the Science Side in general for winning the war (despite the fact that they did not choose Fiamma to be a representative of the Magic Side).
During the war, many member had eithr participated or wathed the war tosee the outcome would be. GREMLIN had wanted nothing to do with World War III and its members had opposed Fiamma of the Right for startng such a thing. After Fiamma was defeated and the Roman Orthodox Church fell under new and more moderate leadership, GREMLIN ha decided to declare their own war on Academy City. Academy City finds out about GREMLIN and they form the organization known as Freshmen to study them but GREMLIN is doing the same thing to them as well.
GREMLIN is similiar to that of other Magic Cabals and is an ideological organization (or criminal according to Misaka Worst). GREMLIN is also concerned about its reputation and is very sensitive to things that they don't do like a bombing. However, GREMLIN is different from other Magic Cabals that have hundreds/thousands of years, it's a concentration of the dissatisfaction and iritation towards Academy City and the Science Side that many magicians had predicted and felt both during and after World War III. Moreover, GREMLIN uses Norse Mythology as their primary source of magic most likely in response to Fiamma of the Right using Christian-based magic for his triggering and him starting the war and being the representative of the Magic Side during the war. Another possible reason for the use of Norse Magic is that Othinus wanted it so she can have it be around her.
It's revealed that the organization itself doesn't excusively use magic. While GREMLIN is a magic side organization, it also uses science and technology such as using balloons to keep Radiosonde Castle afloat and is also exemplified by Kagun Kihara who is one of the organization's main scientists and is the main source of help for members who often rely on technology. It's also revieled that GREMLIN has the capability to face off against the Imagine Breaker ability as seen by Cendrillon and Saronia A. Irivika. They also appear to have no problems casting members aside if they no longer require their services as was done to both Cendrillon and Saronia. Members of GREMLIN also serve Othinus believing that since she is a magic god, she will be able to fufill all of the wishes and desires that the members of GREMLINN all have. Due to the devoution towards Othinus that all members have towards her, she ends up using all of them as pawns and after she defects from GREMLIN, they all go after her for revenge because of their personal desires and wants them to be fufilled.
GREMLIN appears to have no official system of membership and it's unknown how enlistment into the organization goes. It's possible that Othinus goes around and gathers magicians and convinces them to join GREMLIN and Kagun was convinced into joining GREMLIN by the persistance ofMarian Slingeneyer.
GREMLIN uses Norse-based magic and Norse-based names for their members as well. This was done in response to Fiamma's Christian magic and as a form of opposition towards Fiamma being the head of the Magic Side during World War III. Many members of the organization have names based off of Norse figures and is typically associated with the type of magic that they use. True members of GREMLIN often change their names to the names of major figures from Norse religions.
The overall heirarchy of GREMLIN appears to be nonexistant based off of Thor's experience in the organization. Othinus is the highest-ranking member being the founder and leader of the organization and everyone else serves under her as her servants and minions. Othinus is highly respected by her followers as members of GREMLIN obey her orders nad her orders only and ignore commands from anyone else outside of Othinus.
- Othinus - Founder and Leader (Defected)
- Thor (Defected)
- Kagun Kihara (Deceased)
- Sigyn (Status Unknown/Presumed Deceased)
- Útgarða-Loki (Status Unknown/Presumed Deceased)
- Cendrillon (Former Subordinate)
- Marian Slingeneyer
- Freyja (Indisposed)
- Saronia A. Irivika - Subordinate
- Artificial Valkyries
- Numerous unnamed GREMLIN Members