The Dark Age (暗黒期 Ankoku-ki) is the term for the era in which a group of radical familias and Gods known as Evilus were able to roam free within Orario and commit all kinds of heinous acts such as the Nightmare on the 27th Floor.
History[]
The Zeus and Hera Familias were the strongest familias in Orario from 1,000 years ago until they failed to defeat the One Eyed Black Dragon 15 years ago, which greatly weakened them and lead to their subsequent exile from the city. Taking advantage of the situation, a group of Gods and their familias allied in order to destroy Orario under the name of Evilus. As a result of this, Orario turned into a place of terror in which Evilus roamed free to commit several crimes and murder adventurers and civilians alike.
Despite the chaos and vulnerable state of the city, the top Familias managed to fight back Evilus and improve the situation over the years; though it still represented a major risk to live in Orario, with it being an even more dangerous place than the Middle Floors of the dungeon.
While there were multiple severe clashes between Evilus and the adventurers, the most important of them took place seven years ago. This war took place over the span of a week and became known as the Great Feud (大抗争 Dai Kōsō), or the Seven Deadly Days (死の七日間 Shi no Nanukakan); it ended up in the loss of several lives, among which were most of the senior second class adventurers.
Nevertheless, the conflict was beneficial for Orario as it allowed the strongest of their assets to level up. On the other hand, it also severely weakened Evilus due to the loss of Zald and Alfia, their main forces during the battle, as well as the Apate and Alecto Familias, which were the strongest familias of the faction.
One year later, in an effort to go into hiding, the executives of Evilus incited Olivas to cause a big event which would later come to be known as the Nightmare of the 27th Floor (27階層の悪夢 27 Kaisō no Akumu). The incident consisted of a Pass Parade of enormous proportions in order to kill a great number of adventurers who had been lured into the 27th Floor. Although the plan worked, Finn managed to deduce it was a trap and, after concluding it was too late to save the adventurers in there, decided to attack Evilus' main base instead. This led to the capture of many of the Gods that were part of the group and them being sent back to Heaven, another major strike to the organization.
Even after all this the era continued for another year until 5 years ago, when Ryuu attacked the Rudra Familia and the rest of Evilus' remaining forces along all of the people related to them as part of her rampage for vengeance.