The Dreamer's Tree Blight is an extremely dangerous and infectious idea. In Elstren, dreams are a literal and physical place to and from which the soul acts as a gateway. Though dreams are mostly isolated entirely within their own planes, dream mages can access dreams and even take things out of them, and very rarely, dreams can also cross over into reality on their own.

Because they are physical places, anything one dreams up does take on a very real form that, under the right conditions, can enter and influence reality. A horrifying result of this is the Dreamer's Tree, a contagious dream that sustains itself within the catatonic minds of anyone who dreams of it, planting its 'roots' into one's mind and completely overtaking it. It spreads its influence through Dreamers, its waking agents.

A Dreamer is a person whose body has become a nightmarish chrysalis for the Tree, their body splitting open in ghoulish ways to reach the Tree's bowers into the waking world. Though dream objects are lacunae, objects unintended by the cosmic plan and thus destroyed by sunlight, the Tree embeds itself deep within the body of its host, hiding from sunlight while using magic to reappropriate the host's organic matter as its own. These agents take many forms, some highly specialized, but all ultimately have the same goal: expose non-infected life to the Tree.

Whenever someone catches sight of any part of the Tree on a living Dreamer, they are considered to have been 'exposed'. When an exposed individual goes to sleep, if they should dream about their encounter in any way, their mind will instantly be trapped irrevocably in the Tree's roots. The Dreamer finds themselves entombed, their soul ensnared in crushing and claustrophobic isolation until it is freed only by their waking body's death.

While someone who is exposed is no more likely to dream of the Tree than they naturally would be, the grisly forms and terrifying powers of the Dreamers make them a traumatic experience that very easily embeds itself in one's mind. It is sometimes thought that the exceptionally brutal presentation of the Dreamers is a deliberate tactic by the Tree to make itself more memorable, and indeed the Tree displays many flashes of intelligence, sometimes maneuvering its Dreamers almost like soldiers rather than the mindless monsters they appear to be.

During infection, the Tree manifests what is called the Acorn inside the body of the host, which immediately begins growing, reaching maturity within an hour. The Acorn is a fragment of the Tree's physical body, and the locus from which it puppets the Dreamer. The Acorn is one of the most lacunic entities ever recorded, to the point that it explodes with the force of a hand grenade when exposed to sunlight, so those fighting a Dreamer in close combat are recommended to avoid exposing the Acorn as the explosion can be lethal at short range.

Dreamers are powerful and durable, but on average slow-moving and cumbersome. They will spend a lot of time wandering around in the sunlight if there are no targets nearby, idly looking for anything that would make a suitable host for the Tree while also seeking out sunlight to photosynthesize with. They do not display much intellect while 'idle', essentially being a mobile plant pot that seeks as much sunlight as possible and attacks anyone it crosses paths with in the process. The few who have seen into the Dream itself report that the Tree lives in a bubble of eternal gloam, so it is often posited that its desire to spread beyond its realm stems from the dying sunlight in its own dimension.

When the sunlight begins to wane or if they simply happen to be in the dark, Dreamers will slowly become inactive, eventually settling into a stasis around two hours after the last time they were exposed to sunlight. These Dreamers are not very perceptive, but are still somewhat alert and can quickly rouse themselves if they sense a possible host. If a Dreamer enters a place with no light for a long time, it will eventually overgrow in the spot it stays in, even in the total absence of sunlight, but no matter how much it overgrows it can still awaken itself and pull itself out of the overgrowth to attack.

In this idle state, Dreamers passively exude 'spores' that produce all sorts of otherworldly overgrowth in the areas they roam. This overgrowth can spread the Tree's influence just as much as any Dreamer, and acts as a way for the Tree to 'anchor' itself to reality, requiring much effort and diligence to extirpate after the Dreamers themselves are destroyed and strengthening the Tree's 'dominion' over an infected place.

Dreamers first intend to infect, and second to preserve themselves. A Dreamer can directly infect someone by holding onto them for long enough, fusing with their body through roots that form a new Acorn inside their body and then separating, but they also just generally menace anyone they can find in order to embed themselves in their memory. If a Dreamer is attacked by a powerful foe that it recognizes it cannot immediately infect, it will retaliate with an array of attacks ranging from biological weapons like bladed arms or sharp teeth to shockingly powerful magical effects. Each Dreamer is different, and will display different powers and specializations.

Dreamers get more intelligent in numbers. When there are three or more Dreamers working together, they border on human intellect, displaying complex teamwork and stratagem comparable to trained soldiers and using their unique abilities to support each other. This can be explained by the Tree's attention converging in places with large numbers of Dreamers, exposing the Tree as a sort of diffuse intelligence that is typically spread thin but can suddenly focus to win important battles and make major strategic moves.

Dreamers do not mind killing potential hosts because a freshly dead host is almost as good as a live one, and can usually easily be resurrected by a new Acorn without much trouble. Dreamers killing potential hosts may exhibit cautious precision, like that of a hunter trying not to damage their catch, further betraying more intellect than one would expect from zombie-like beings.

Fighting the Dreamers is difficult because exposure is extremely risky. A single exposure means that, without wiping their memory, someone who has seen a Dreamer is thereon permanently at risk of spontaneously becoming a Dreamer no matter how much time passes. This is perhaps the greatest threat posed by the Tree--anyone who has seen it could become a new outbreak, even decades or centuries later, under the right conditions. It is impossible to know how many people have been exposed.

Due to this, very strict measures have been put in place. Any organization responding to the Blight undergoes rigorous protocols and training to ensure that everyone who spends any time exposed to the Blight will have their memories wiped of such exposures. Some factions have taken to training special units that use extrasensory perception and blindfolds to completely circumvent any risk of exposure as well, especially the Flock.

There is little hope of permanently eradicating the Blight unless the dream itself is destroyed, a subject of intense debate and magical inquiry. Without this, it is likely that at least one exposure will slip through the cracks in each event, resulting in a ceaseless cycle of spontaneous outbreaks. So far, a method of destroying the Blight at its source has yet to be discovered. The Dream itself is not a new dream for each Dreamer but rather a singular dream in which manifold dreamers are entangled, so this approach does have some promise.

Once a quarantine has gotten rolling, it's not very difficult to prevent an outbreak from spreading any further. However, because each Dreamer is an exceptional threat on its own, it takes large and complex operations and a lot of manpower to overcome the resistance that Dreamers pose and purge a town of the Blight. All of this extra manpower inevitably complicates the process of ensuring that every single agent is prevented from becoming another carrier for the Blight, to say nothing of the possibility that the Dreamers actually overcome the first round of quarantining and rout the authorities, which has happened more than once.

Worse yet, the Blight seems to continuously evolve in response to the tactics of authorities, notably establishing anti-magic wards that jammed teleportation to hamper supply lines during quarantining and even learning significant figures and targeting them on the field. The pressure to destroy the Tree before it grows out of control only ever seems to mount.

In areas where the Blight is present in large amounts, reality subtly breaks down. A Blight outbreak is measured in five stages, and the fifth stage involves the Tree's utter domain over the infected land, exuding magic from the tendrils of its vines that warps local reality to the Tree's whims. In a Stage Five outbreak, the sky over the affected land begins to appear like that within the Tree's dream, and the Tree itself can be seen looming like a vast mountain over the horizon, though this is merely an illusion.

Where or how the Blight originated is unclear. It is often thought that the Dream was somehow deliberately created as some kind of weapon or religious subject, as its infectious nature is highly anomalous--if such a malignant dream were possible spontaneously, surely such a thing would have happened before, but this is quite unprecedented. Outbreaks of the Blight have been ongoing since the beginning of the Black Tide roughly four months ago.

Currently, the Blight represents a disturbing threat, but it is considered tenuously 'under control' while Woodveil's three main factions work together on finding a way to destroy the Tree at the source. Recently, though, a very severe outbreak occurred in the major port of Hamish where over ten thousand people were infected, leaving the city under a quarantine-siege as all three factions and the Flock desperately wage an all-out war against the Dreamers there and displaying the apocalyptic potential the Blight holds.