348 Black and the Dragon Eggs

The Abyss was a world formed from the combination of countless shattered or distorted plane. All of the innumerable legends and myths viewed it as the place where the evil and the twisted congregated, the root of all suffering and despair.

There were many different conjectures regarding its origins, among those was a bold one made by a demonologist who had traveled within the embrace of the Abyss itself and carried out decades worth of research. He believed that the Abyss was, in fact, the graveyard of the multiverse, and that those small, misshapen planes were the shards left behind after the death of infinite worlds. 

And the door to the Abyss is the passage that connects it with other worlds.

During the first Abyssal invasion in the Glorious Era, what was perhaps the largest Door to the Abyss known since the birth of the multiverse opened in the outer reaches of space over the world of Mycroft.