Annaer

"It's hard to explain... there's this thing, right, when a person gets hit with somethin' so hot it just turns 'em to ash. The wall behind 'em gets this sorta shadow, ya see, like an outline of who was there. That's them, that shadow is. Only what hit 'em wasn't fire. It was bigger'n that, somethin' that hits so hard you lose who you are. For them it was sorta like... it's like how ya reckon the world works was turned to ash and a single thought is that shadow. Ya know what I mean?.... No, no you wouldn't, I suppose. Somethin' like that hasn't happened in an age. But imagine that... you bein' a thought, not even knowin' if that thought is true."

- Blind Guardsman, asked to describe their Annaer

Annaer are not sinister, just unfortunate. There is little else that isn't difficult to explain, for what scholars know of these creatures has only been cobbled together after they were discovered and only after they've been bonded to a person. So to speak about their beginning we must skip to the end.
Annaer can bond to a person. This bond is more of a forging of minds than a bond really. Annaer are simply a haggard thought until they are bonded. Only after a connection is made does the creature gain some form of sentience. These creatures are a shard of a mind, a single line of reasoning that may or may not be coherent. When a connection to a humanoid is made, the Annaer can model its consciousness off of the person's, much like how a crystal can grow from a small chip off another crystal. The savvy reader may wonder if the seed that the Annaer bases its restructured consciousness from affects how that consciousness is restructured. It appears that yes, it does and is likely the reason why Annaer and the person it's bonded to share such a strong connection. Angry people breed nefarious Annaer, good people breed righteous Annaer and so forth. Seeing yourself reflected in another is a powerful relationship. Some would say that that is what love is, finding yourself in someone else. Mages are still experimenting with love, further research is needed to understand this concept.
As they bond and grow, Annaer change their form as much as their being. These creatures frustratingly keep themselves hidden however, even from other Guardsmen, so what we know had to be pried from the dull minds of the Blind Guard who can see this process. From what has been gathered from multiple accounts of Guardsmen, they seem to bud, much as a coral or fungus would. A small speck of ash floating in the wind eventually becomes a pebble, which eventually becomes a skull. Over the course of a month or so, what began as a speck has now become a shade. Just as the consciousness of the Annaer is based on the person it bonded to, so does the form of the shade seem to be unique to each Guardsmen. The depiction above was given to us by one of the Guardsmen when asked to draw the Annaer. From all accounts, all Annaer look similar to this, drawn out skeletons in various levels of corporeation. She did mention that she tried to draw this more realistically, but it's hard to show how black can be blacker than black. Apparently these creatures can be seen even in the darkest cave. Likely just a lively imagination from a bored Guard.
Once fully formed, they can speak to their Guardsman. They seem to be an odd sort however. Despite being bonded to, what appear to be at least, functional minds, the thought that they had lived as for an age seems to be the dominating schema in their full consciousness. For example, an Annaer who was of the mind that, "Screaming winds make subtle choices," as one such Guardsman reported, seems only to concern itself with the passage of time and the effects of time on things. Another Guardsman has reported that their Annaer was germinated from, "Tall trees shatter and live happy," and is enraptured by a particular peninsula found on the northern edge of Yodren.
These idiosyncratic indulgences are hardly deleterious to the Blind Guard nor do they impact their ability to execute their duties. More concerning is the ubiquitous, all consuming fervor with which the Annaer dominate magic. This zealotry for command and control of any magic near them is astonishing. Mystra, in all of her command and glory, permeates the Weave through all living things. Not an ant nor blade of grass does not contain magic. Yet the Annaer are able to expunge the Weave, create a void in the pattern so pervasive, even creativity is negated. Nothing approaching the concept of altering reality can exist within this zone when the creature wills it. Scholars still struggle with the concept. How can a fractured thought that couldn't exist without the will of man fly in the face of a Greater God's authority? Theories abound but the one most corroborated by the Guardsmen seems to be a devotion to Mystra. That Mystra controls magic as much as she gives. If correct, the Annaer seem to have formed a bond with a Greater God much as a paladin or priest would. We cannot rule out the possibility that it is more sinister, that it is more akin to the agreement made between demon-owned and their master. Guardsmen talk about "penance" or "regret" and "sorrow", as if the creatures' pasts were something to atone for. The Guardsmen have deluded themselves into believing that their Annaer are attempting to correct their disastrous past.
This theory gains more weight as we get the details of how these creatures were created. They are not easy to interrogate since we cannot see them, hear them, interact with them in any way and have to trust the lesser minds that translate ramblings from a monster two steps from madness. What we have gathered however, is startling. The Annaer appear to be a relic of the Second Age, shattered fragments of the people who were caught in the Cataclysm when it was formed. We knew from historical records that the Cataclysm was formed from powerful spells, at least 10th level or higher. What we do not know is what those mages were working on. So much research cannot be recovered from the frustrating reservation of these failures that called themselves mages. Their illogical and fanatical devotion to keeping magic restrained, to stay within the confines of Mystra's direction, restricts progress in an intolerable and unacceptable fashion. Research is being conducted to better interrogate these... things.
Indeed, the life of an Annaer before it is uplifted betrays how far they've taken their irrationality. Only when the coincidental accident of two experiments going awry simultaneously were we able to even detect these things existed. An experiment attempting to bind Truesight to a pair of binoculars and another attempting to open a portal to the Far Realm failed in such a way that we were able to see into a different reality with Truesight. There we caught these parasites, feeding off of the font, Whitehall's very beating heart, in the form of wisps. During extermination, we happened upon the ability to bond these creatures to the magically inept. Rather than purging these abominations from our town, we gracefully allowed them to stay and use them to control our experiments.
For those of you who have misread this bond between person and creature as some form of boon, for those who wish to have a monster follow you for the rest of your days, listen well. Once bonded, the person can have no connection to magic. They can never again cast a spell. Enchanted weapons and armor fail. Magical means of transportation will no longer convey them. Runes and sigils are lost. They cannot be touched by spells, true, but this means they can never be healed by a mage, nor benefit from any other boons Mystra has gifted us. To choose this bond is to choose to blind yourself, cut yourself from the world beyond this one forever. Choose carefully.

Basic Information

Anatomy

Annaer Before Bonding: These creatures can only be seen, then caught, by opening a tear in reality through a hyper-potent form of Truesight. Prospective Blind Guardsmen are of course used for this, often they just end up blinded or killed. They have been reported as being small shadows of black, wisps about the size of your fist.
Annaer After Bonding: Annaer may change their proportions depending on the Guardmen they've bonded to, but all take on the ghostly aspects of shades. Long limbs, dripping shadows, and little more than deformed skeletons. Fortunately, only the Guardsmen they've bonded to can see them. Even empowered Truesight fails to catch these creatures.

Genetics and Reproduction

Assuming the Cataclysm isn't producing more of these unbonded Annaer, there are a finite number of these beings. Bonding or exterminating the population will allow us unfettered access to Mystra's more impressive gifts.
Of more concern is the mysterious reasons why an Annaer will bond with a person. Not all those who attempt to fish an Annaer from that other reality succeed. Sometimes a Guardsmen doesn't need to try at all, just finds themselves bonded one day. Sometimes the Annaer kills their person or shreds their minds, creating a drooling mess we have to remove. It is only a select few that create stable and beneficial bonds with the creatures. Research is ongoing in discovering what makes these magically useless people so exceptional.

Dietary Needs and Habits

Unbonded Annaer consume magic. They are voracious creatures, swallowing spells whole. The font within Whitehall likely attracted these creatures all the way from the Cataclysm and the reason why the castle is lousy with them. It is unknown whether they afflict any other unfortunate researchers.

Additional Information

Perception and Sensory Capabilities

Since bonded Annaer are true reflections of the bonded Guardsmen's minds, it should be no surprise that a powerful telepathic bond is shared between the two. The experiences of the Cataclysm give the Annaer, and thus the Guardsman, the dumbfounding ability to detect magic, no matter how faint, from an absurd distance. Even the intent of experimental magic seems to draw the Guard. At least, no one has ever had to ask the Blind Guard to oversee an experiment, they've just known to show up and in appropriate numbers.
Research has surrounded these abhorrent pests for one reason. The ability of an Annaer to negate magic is more sinister, more pervasive than a simple Nullify Magic spell. Thought leaves the targeted area. Imagination withers. Nothing but direct perception of the world is available to the target. This blinded view of the world gives a direct, unfiltered lens to pure reality; what the physical world truly is without the veil that emotion overlays our sight, how imagination wills the world to work, or misperceptions of our fallible senses. When one can see how reality truly works, you can start to bend it. Within an area devoid of anything besides a cheerless world, the Blind Guard manifest weapons or manipulate the environment to end what threat there is. The fights never last long.

Geographic Distribution

• Whitehall