Delver

The delvers, sometimes called the eyes, are ancient, extra-dimensional beings that live in the nowhere, the space beyond the world utilized by numerous cytonic abilities. They can occasionally emerge into the physical space, where they pose major threat to all living beings.
== Appearance ==
=== In the nowhere ===
Delvers can be seen by cytonics who attempt to use their powers. Initially, they appear as hundreds of pinpricks of light across a vast blackness, which open to reveal small, white eyes that watch the cytonic. The effect is often compared to the attention of the entire universe suddenly focusing on the cytonic. The longer one observes the eyes, the larger they seem to appear. Perceiving them leaves a person with a sense of cold that persists for hours afterwards.
The appearance of delver eyes is preceded and accompanied by a pleasant sound, akin to a thousand musical notes playing together in harmony; similar to the sound of FTL communications to cytonics. It grows louder the closer one is to seeing them.
=== In physical space ===
When sufficiently antagonized by cytonics, delvers can appear in the real space. The emergence begins as a distortion in reality from which everything manifests. First is the appearance of the core, or the heart, which takes the form of a sphere of pure black. Afterwards the delver maze grows around it -- a confusing, seemingly-random array of dark, hollow spires jutting out in various directions, connecting together to form a network of traversible tunnels. Finally, the delver maze is enveloped by a dense cloud of particulate dust, filled with raging storms and many-colored lightning.
A fully manifested delver is titanic in scale, enough so to have its own gravitational pull. The one summoned by Brade is somewhere between a massive moon and a small planet, while the one called over Detritus in ancient past was capable of enveloping the entirety of the planet.
==== Interior ====
The inside of a delver is extremely chaotic, with the particulate cloud in a state of perpetual storm, crippling both vision and communications. Any person that enters the maze will start to hallucinate, seeing passages and objects that aren't there. The hallucinations are different for every person -- as such, they are generally ineffective against groups capable of coordination, or dione drafts.
At the center of the maze lies the heart, protected by an illusory membrane. Unlike the rest of the delver, the area immediately surrounding it has atmosphere breathable to air-using species, like humans or diones. A hole leads into the heart proper, which is black on the outside, and utterly white on the inside. The heart is a place of perfect serenity, free of any disturbance, although cytonic and radio activity forms small holes in its walls, which when seen by cytonics outside the delver form the eyes. The holes are inherently unpleasant to all who perceive them and make distressing sounds.
The delver mind resides within the heart; while its true shape is uncertain, it seems to take the form of the person who interacts with it.
== Abilities and behavior ==
=== Hatred of cytonics ===
Delvers are incapable of most emotions; rather, they reflect all that they sense outside. This being said, they can hear and perceive any intrusion into the nowhere. It appears to cause them immense pain; as such, they utterly despise cytonics, and grow more hateful the longer one holds their attention. Extreme and prolonged cytonic "screaming" can and will cause them to transition to the physical world in an attempt to quiet it down. Superiority scholars speculate that a species needs to develop particularly skilled or powerful cytonics for delvers to pay attention.
Once delvers leave the nowhere, they can also hear radio communications, which causes the same hateful reaction in them. They perceive both types of signals as noise, making them grow aggressive and go after the strongest source in vicinity. When they are done, or otherwise run out of targets, delvers will roam outer space for anywhere between several years to several decades before fading back to nowhere.
It's heavily implied that delvers do not understand that the noises are caused by living, sapient creatures; the revelation of it seems to cause at least one of them considerable distress and make it depart back into the nowhere of its own volition mid-attack.
=== Tangibility and deadliness ===
Delvers have a strange relationship with tangibility -- while the delver maze has discernible, unpassable walls and floors, the delver itself can seemingly pass through physical matter, allowing it to envelop entire planets. However, standard shields, such as ones mounted on starfighters, can stop the delver from passing through, at least for a time.
When a delver does pass through a living being, it causes the latter incredible physical pain. The person affected appears to shrink and fold in on themselves, as though under enormous force, before vanishing into thin air. This apparently doesn't require any effort or attention from a delver; as such, the being can cause utter devastation simply by passing through an inhabited area.
=== Cytonic abilities ===
Despite their hatred of cytonics, delvers seem to have at least some of their abilities, including:
* Illusions: much like "mind holograms" used by the Krell to deceive human cytonics, delvers can create illusions for people that enter their mazes. The illusions are extremely chaotic, overwhelming and nonsensical; however, each is specific to a particular person. As such, two minds are required to discern them from reality. Cytonics seem to suffer more from this ability, perceiving powerful emotions and illusions emitted by the delver.
* Sense: delvers do not possess any discernible eyes; rather, they perceive cytonic and radio signals as sounds.
* Detecting cytonics: delvers are capable of sensing other cytonics, both in the nowhere and, seemingly, in physical space.
* Teleportation: delvers are capable of FTL travel while in physical space, and can jump between star systems in an instant.
Additionally, delvers possess strong telekinetic abilties. They can somehow create and control embers, large rocks akin to asteroids, and shoot them outside of themselves at targets. Close by, as well as within themselves, they have much greater control, and can use embers to chase down and destroy ships.
=== Direct contact ===
When a delver and a non-delver's minds meet, there's a level of mental "pollution"; the other person will begin to perceive the noise of the world at large as unpleasant, and feel hatred towards other living beings, along with a distinct sense of megalomania. The person's mind also appears to expand, as though they can perceive the entire universe all at once. Such thoughts vanish within several moments. The effect is amplified when the person touches the delver's mind directly.
On the other hand, at least within the heart, a cytonic can push their own thoughts onto a delver, bringing their mind down in scale to see from a living beings' perspective. This correlates with increase in empathy in the delver, and sudden ability to feel more emotions, including regret and horror.
== Safeguards ==
The danger posed by the delvers has made it necessary to take measures to avoid catching their attention. Such measures were known even to the ancient humans, who prescribed radio silence and shielding all fast processors. 
The chief safeguard, maintained both by the people of Detritus and by the Superiority, is to abandon all but the most crucial cytonic abilities and technologies, and surrounding inhabited spaces with cytoshields, which clamp down on and limit cytonic activity. Cytonic communications have likewise been abandoned, and radio usage is greatly limited, with cables replacing it where possible. Artificial intelligence has been banned, and in the present times, AIs are regarded with fear by the people of the Superiority. However, it seems that, much like few scattered cytonics don't pose a threat, lone AIs are capable of functioning without drawing the delvers' ire. 
The one cytonic technology still widely in use is FTL travel; to maintain it without delvers coming through, the Superiority uses taynix, a non-sapient species of cytonic slugs, as a distraction. However, in the years since the last delver had vanished, places such as Starsight have come to once more rely on wireless communications, posing a major risk when one reemerges and targets them.
It is unclear how effective many of the safeguards are against delvers. FTL travel and reckless use of AI are known to summon a delver; however, cytonic and wireless communication may only attract a delvers presence once it has entered the physical universe.
== History ==
===Ancient Delvers===
According to Spensa's second vision on the Path of Elders, an alien species with access to advanced technology created a "beast" which wiped out the majority of the pre-Write cytonics before being defeated, causing a long period of isolation that cut off most races from each other and causing humanity to forget about the existence of cytonics until their rediscovery by Jason Write. In the vision, this "beast" appeared similar to a delver (shining white eyes in a featureless blackness), but it is unknown how similar it was to modern delvers.
=== First appearance ===
Delvers were an artificial intelligence that went into the nowhere and evolved to a higher form. However, the AI at first only experienced emotions over a period of days when its creator, Jason Write, died. With the pain overloading its mind and not understanding how to deal with any sort of emotion, it expelled all memories and personality, then copied itself over and over to avoid any sort of pain or loneliness whatsoever.
The first known appearance of a delver occurred during the second of the human wars. During that time, mankind built facilities on obscure planets as part of a weapons program hoping to summon and control a delver, with Detritus being one such base. They have also built stations to train people in handling the delvers. Though their attempts were successful, the beings proved impossible to control, and in some cases, the cytoshields proved insufficient, leading to delvers destroying the very people who sought them out.
In total, thirteen delvers emerged into the physical world. They rampaged throughout the galaxy for the next few decades, destroying world after world, before eventually fading away one by one. From then on out, however, they were a constant presence in the nowhere, observing all visitors. For this reason, Superiority, as well as human enclaves, drastically cut down on the use of cytonics and wireless communication, so as to avoid drawing them in again.
=== Second attempt ===
A century after the Third Human War, the delver threat remained in the public consciousness, although the protective standards grew far more lax. At this time, Winzik, head of Superiority's Department of Protective Services, conceived of a plan to once more deliberately summon a delver and control it, and to use it as a weapon against those who'd go against the Superiority. The lynchpin of his plan was Brade, a powerful human cytonic under his command.
With rumours of delvers being close to reemergence -- possibly fuelled by Winzik's propaganda -- Superiority set up a program to train people to fight them. They also developed a supposed weapon that could get rid of them, though in reality, the "weapon" was a cytonic device that would lure a delver to a different planet. This was the primary method by which Winzik would "control" the delvers: set up the lure with coordinates to whichever place he wished destroyed.
=== Reemergence ===
When Superiority arrived over Detritus for a decisive battle, Spensa quickly realized that Brade intended to summon a delver right there and then. She advised Detritus to cut off all radio communication in anticipation of the event before pursuing. She, and eventually others from her training flight, chased after Brade, hoping to kill her before she could suceed. Eventually, they managed to pin her down, although in her would-be final moments, Brade managed a summoning. 
After the delver emerged, Spensa tried to send it away, to the star system in which she and the other trainees had practiced. While she succeeded at dissuading it from attacking Detritus, the delver instead went to Starsight. Spensa and her flightmates followed, hoping to take it out before it could kill everyone on the space station. With assistance from Morriumur, Spensa managed to reach the heart. There, she communed with the delver and managed to show it that all the annoyances that the delvers despised were living creatures. This seemed to horrify the delver, which quickly returned to the nowhere.
== Trivia ==
* The name "delver" is mentioned once in Skyward before being properly introduced in Starsight; whenever the delvers are referenced in Skyward, Spensa uses "the eyes" instead.
* There is a deliberate similarity between the appearance of the delver heart and the communication chamber from Defending Elysium.
* Brandon once began writing a science fiction novella called The Eyes, inspired by the Fermi paradox, the question of why we can't find any aliens despite the statistical probability of their existence. The story remains unfinished, although a chapter of it was posted as a reward on the Writing Excuses Patreon page. Its setting was eventually absorbed into the Cytoverse, with one of its alien races appearing in Starsight. Given the title, it's possible that delvers originated from the story.
* Much like Calamity from The Reckoners series, delvers are extradimensional beings from a dark and quiet place that hate the noises of our world and the people who make them. When asked about this similarity, Brandon said there is a "very, very loose connection" between them and that The Apocalypse Guard series was originally intended to be a bridge between these things, though he was unsure if that bridge would remain after he finished fixing the first Apocalypse Guard book.
== Notes ==