Ragnarök

Ragnarök
A term initially uttered by the Emperor of Britannia when Lelouch forms his Geass contract with C.C.. With the use of the Sword of Akasha and the Thought Elevator, and two Codes, the Emperor can use it to force the collective subconscious of human beings onto the surface of their mask and affect reality, making all humans, both living and dead, into one being. For this reason, the Emperor has connected every thought elevator on the planet. He then intended to unleash Ragnarök using the thought elevator in Kamine Island. This contract was made between Charles zi Britannia, Marianne vi Britannia, C.C. and V.V., where they would destroy the gods and unite all humans, living and dead into one being. This plan was thwarted by Lelouch vi Britannia when he used his Geass to compel the gods to keep existing and to keep time moving. This resulted in the death of both of his parents.

Trivia
The concept of Ragnarok is very similar to the third impact of Neon Gensis Evangelion, both in the idea and the way it is carried out, a plan where a secret cabal of the worlds elite and powerful work to unite all of humanity into a single entity with the purpose of saving it.