Vagary are keystones that have come to life, and now seek to replenish the mana they have lost. They start off with very little intelligence, and as they gather mana their intelligence and capabilities increase. If a lesser Vagary manages to eat enough mana, then they will evolve in stages. First, they become a mid-tier Vagary, then a greater Vagary. If a Vagary gains its maximum possible amount of mana, they have three options. They will either transform into an aberration, a newly formed keystone, or they become a near-divine being known as a Manaborn.
The Manaborn and aberration are extremely dangerous and usually kill anything on sight if it isn't familiar with it. If they can get past this stage in their life, and become recognized as pillars of Kurose's kingdom, they are allowed into his ilk and are deemed mana lords.
The Vagary are a unique abomination as they do not share their origin with any species. They are unable to reproduce on their own and instead infect existing communities to grow their brood.
They are intelligent but typically take their commands from the strongest Vagary present when in a group. Their obedience will cause them to willfully end their own existence for the strongest of their kind to survive. The first Vagary originally came from clusters of mana in the Abyss, created by a tainting of mana, which gave life to a being that should never have existed . They emerged from keystones and then converted other forms of life into what they were so that they could better protect themselves.
Many Vagaries are found within the Abyss. Over the years that they have spent under the leadership of Kurose and his ilk, they have found themselves slowly expanding into more civilized cultures in secret. Due to their adamant ability to shapeshift some of them act as spies, beggars, and impersonators to gain footholds in foreign societies.
The Vagary are naturally powerful magic users, second only to the Gods, with Hybrid Sorcerers follow after them in raw magical strength. Their strength has the cost of needing to continually consume. Their mouths span from just above their slitted nostrils and travel all the way down their abdomen. They can devour whomever or whatever they want as quickly or as slowly as they desire. They have tongues that they drag across the ground for tracking ley lines and large portions of mana. The tongue contains vital organs that when damaged, are easily replaced. If removed while low on mana could paralyze the Vagary until enough ambient mana was gathered to regenerate said organs.
In some cases, Vagary will permanently alter their bodies to take more unique and specialized forms. Some people wonder if there are Vagary living in their own villages.
In some Vagary friendships pacts are made. Finbel Parrolette discovered the identity of the creatures known as Vagary and proved that they were intelligent. She would later develop the taboo art of forming a pact with a Vagary which would exchange one's sanity and nature for mana and strength.
In an extremely rare case, a Vagary could make a pact with a God, this process is uncharted territory for all beings except one. Kurose, the God Eater, is the only person to have achieved this through the process of eating the god known as Dauoin. A God Eater is a Vagary Hybrid who has eaten a God, and in doing so has become a place of power. This person can control Vagary, and turn mortals, hybrids, and birthless into Vagary via a corruptive aura, and will continue to have an insatiable hunger for divine flesh.
Vagary will live indefinitely unless their heads and tongue are removed from their bodies. This is not an easy task, and even more complicated the older the Vagary is.