The Abyss

The Abyss is a mysterious extra-dimensional entity. Nobody knows for sure what it is ontologically, or even whether it exists in the same sense people and gods do.
Virtually every person in any region of Nys knows a version of a myth about the Abyss. Stories, legends and theories intertwine, often disagreeing on most details and even on core concepts. The only common ground is the link between the Abyss and chaotic, soul-corrupting energies.

The Sources

Nowadays, there are two trusted sources of information about the Abyss.
The first one is Damparo, who fought an archdemon at the end of the Second Era, more than 2000 years ago. His journey led him to discover many truths about the cosmos, especially regarding the Abyss. Damparo claims he can't fight, or even interact, with the Abyss anymore since knowledge and exposure to the Abyssal energies caused him a Corruption Trauma.
The second source are the Cosmos Wayfarers, who travel across the kanvæ in a neverending quest of defeating the Abyss and protecting the kanvæ from corruption. Their information is the fruit of their understanding of reality, which is, by their own saying, erroneous and partial.

The Theories

During the years, philosophers and scholars merged information, known facts and some guesses to come up with coherent theories. Recently, the Moon Church funded a team of experts to categorise and reorganize the most spread stories and theories about the Abyss, with the goal of having a clear idea of the enemy they're trying to fight.
The scholars travelled through Nys as much as they could, gathering information and recording myths and theories. After six years of studies, they concluded a book, "The Nature of Our Enemy", where they synthesised the knowledge they collected along the way.

They divided the legends into three core categories, based upon the perceived essence of the Abyss, its ontological status. While some of the theories fitted well into one of these categories, some others crossed the boundaries between them. Even though the division presented these faults, it was a first attempt at organizing information and was welcomed as a great achievement.

As a Concept

The most abstract interpretation of the Abyss regards it as an abstract concept.
In this frame, the Abyss is not something that concretely exists, but rather the name people gave collectively at the feeling of chaos and corruption they experience in presence of abyssal energies. The Abyss would not have a purpose, nor an origin. It is validated by the people themselves who give sense to it through the common agreement that corrupting energies can spread and are dangerous.
These theories can be the most optimistic or the most pessimistic, depending on the details of each one. On one hand, there is no real enemy to fight, making the war easier, limited to warding against corrupting energies. On the other hand, it is impossible to win the war since chaotic energies exist, even though in a small measure, wherever living creatures are.
The Abyss is widely understood as a concept in the Arkadhian New Empire and Cajena.

As a Place

Some theories propose the Abyss is a place, maybe a kanva. They are usually more recent stories, spreading with the wayfarer's travelling experience.
According to these stories, the Abyss exists somewhere in the cosmos as an actual place. If it was a kanva, it might have a main portal and could be destroyed by killing its guardian.
Some people suggest the Abyss was the first kanva ever corrupted by chaotic energies, thus marking a birth moment for it, effectively making the Abyss an existing thing from a concept. Some others suggest it is a place, but not a proper kanva so that it would not have an entrance point, nor a guardian to kill.
In some of these theories, the Abyss has a purpose but is usually not a living being on its own. Its goal would be the same as the archdemon guarding it, or a blind hunger.
These theories are popular among the Cosmos Wayfarers and are the official position of the Moon Church, at least until more information is acquired.
Related myths: The Devouring Abyss.

As a Living God

Usually regarded as the worst possible scenario, some theories suggest the Abyss is a living extra-dimensional entity, more powerful than any Nysian god.
Constraints, different in each theory, would limit its movements and range of action, forcing it to rely on avatars, emissaries and the like. It would live in a dead or corrupted kanva somewhere in the Cosmos and would be able to only move between corrupted kanvæ (depending on the version).
In this frame, the Abyss would have a clear and precise goal to pursue. Many people believing in one of these stories claim its main target is to corrupt Nys since it would give it access to a vast world and many kanvæ. In this light, the wayfarers are collecting and protecting as many kanvæ as they can, bringing their access point to the Crossroads.
These theories are widely accepted in the Dark Lands and the Sun Desert Kingdom. In particular, the Dark Swan is considered an Abyssal emissary.