Ragnarok Quest

The Twilight of the Gods (神々の黄昏, Kamigami no Tasogare), more popular in the name of The Ragnarök (ラグナロク, Ragunaroku) is a quest, generated by the Cardinal System's «Automatic Quest Generation» function, that covers Muspelheim, Niflheim and the rest of the Nine Worlds. It is also the main focus of Sword Art Online: Project Ragnarok.

Initiation
Unlike most quests present in MMORPGs, the Ragnarok Quest didn't need any kind of action to be initiated. It was an automatic (and compulsory) quest enforced by the Cardinal system.

The sound of the Gjallarhorn would echo all throughout the land of the faeries, originating from the World Tree, and mark the beginning of the apocalyptic event. The new maps would be completely unlocked, introducing a new brand of difficult monsters and bosses.

Location
The Ragnarok Quest takes place in all of the Nine Worlds, with Muspelheim and Niflheim acting as dungeons, while Alfheim and New Aincrad (Midgard) retains their status as settlement areas for players. The World Tree will also serve an important role in the quest, as the top of it had been the chosen location of Asgard.

Objective
The main objective of the quest is to stop Ragnarok from becoming a reality, as failure to complete this would mean the deletion of every player data, and ALfheim Online will undergo a force restart, using the Cardinal's back-up data of the different maps to recreate and create a new beginning. The Ragnarok Quest is further divided into more sub-quests.

Revenge of the Bifrost Quest
The rainbow bridge, Bifrost, had been broken by the forces of Muspelheim, and the only connection to Asgard, the realm of the gods, had completely been cut off. In order to stop the fire giants from turning the remaining of the World Tree into ashes, Surtr must be defeated.
 * Boss: Surtr and Sinmara
 * Location: Muspelheim
 * Monsters: Fire Giants

Return of the Light Quest
The God of Light, Bealdor, was killed by Loki and sent to Hel's abode, Niflheim. Without him, completion of the quest would be almost impossible. Venturing into the realm of ice and defeating Hel would mean acquiring Bealdor's Soul. Bealdor can then be resurrected by the means of a spell.
 * Boss: Hel
 * Location: Niflheim
 * Monsters: Frost Giants

Devouring Apocalypse Quest
Jormungand has risen and set out to fulfill its role, to devour Midgard.