Diclonius

“	It is not the strongest of the species that survives, not the most intelligent that survives. It is the one that is the most adaptable to change.	”
–Charles Darwin

The Diclonius are a newly evolved species, arising from and very similar to normal Humans, but possessing psychokinetic abilities far beyond any Human. For reasons that may be cultural as well as biological, they are often at odds with Humans to the point of threatening to replace them as Earth's dominant sentient species.

In The Series

While Lucy was indeed the first and 'Queen' Diclonius, her late mother was the source of the mutation that birthed the virus in her children. Lucy's birth fulfilled the messianic expectations of the well-heeled and highly positioned Kakuzawa clan, some whose family members possessed a genetic mutation that gave them vestigial horns. Despite this, their cult-like beliefs, and the world-shaking steps taken on behalf of Diclonius supremacy by Chief Kakuzawa, the two groups were unrelated. Sadly, the treatment of the Kakuzawas in feudal Japan and their reaction to it would foreshadow the relations of Humans with the actual Diclonii centuries later, including the ironic way the family treated Diclonius individuals in modern times. Chief Kakuzawa also believed that the Diclonius were the Oni (Demons within Japanese Mythology) meant to surpass and replace Humans when their messiah was born.

Mentioned in Episode 3 or 4, Diclonius appeared before Lucy's birth. However, none before her were capable of reproducing, and many died in infancy. This idea seems to be an anime-only assertion not present in the original manga. Check here for a fuller explanation.

Anatomy and Physiology

The differences that separate Diclonii from humans are both internal and external. The most noticeable difference is their horns on the parietal section of their skulls. Most often, these horns resemble cat ears from certain angles. In older chapters of the manga, the horns resembled elf ears but as the mangaka's art style kept fluctuating they slowly took on a more inadvertent cat-like appearance until that remained their shape for the rest of the series and in the Anime adaptation. At times, even later in the manga where the art improves, the horns can take on a pointy bump-like or vague triangular shape which seems to be caused by drawing inconsistencies in the manga. These horns are a mixture of bone and cartilage. The manga states that Diclonii falls into a temporary coma if they lose one of their horns, and would never return from their lethargic state if they lose both horns. However, Lucy's horns grew back twice: within a matter of months for the first time, then over several days the second time.

Another notable difference between them and humans are their hair and eye colors, though this difference varies from manga to anime. In the manga, Diclonii possesses hair colors of many different shades, from pink to purple to blonde. On colored art, Lucy, Nana, and Mariko all have green eyes but it is unknown if this applies to all other Diclonii and is likely just a mere coincidence as distinct colors are never mentioned as a specific trait for Diclonii. In the anime, however, their hair colors are more unified, being a variety of pink hues. Likewise, their eye colors are variants of red that can range from very dark red to pink. This design change from manga to anime was most likely chosen to make them seem more obviously aliens from humans.

Inwardly, they differ from humans at their pineal gland. Normally, the pineal body is the size of a pea and located in the center of the brain between the two hemispheres, but for a diclonius, it's the size of an egg and wedged against the frontal lobe. The pineal gland appears to be the source of their vectors since Diclonii have had their vectors disabled in series by way of Nana prodding the front of their skull with her vectors and by the mind control devices implanted by the Diclonius Research Institute's scientists. These vectors resemble hands, but cannot be seen, touched, or otherwise acted upon by outside forces (aside from instances in the anime where vector-on-vector grappling takes place). Vectors spread the Diclonius Virus to humans via touch, and they can manipulate objects, act as shields by decelerating projectiles, and slice through things, giving them the potential to be massively destructive if used offensively. Against humans, they are almost always lethal. Their vectors usually have a limited range of a few meters. Lucy's can extend to two meters, and while Nana, Mariko, and her clones are shown to have either more vectors or greater average range, Lucy's raw power became robust enough to threaten the world. Ultimately, using her vectors to world-destroying capacity compromised her body's integrity until it fell apart.

Diclonii have the innate ability to detect one another, such as when Kurama released Nana from the offshore laboratory to search for and retrieve Lucy. Even this ability had limits, as she could not sense her target when she was in her childlike Nyu personality, nor could she sense the Mariko clones when they were under the control restraints placed upon them by Nousou and the Agent during their assault on Maple House. Likewise, Nyu's presence could not be sensed by other Diclonii.

Diclonius are quite intelligent. However, the Diclonius are also just as emotional as Humans, often more so. Once they reach the brink of sanity, some hear a voice that claims to be the directing voice of their DNA, urging them to kill as many Humans as possible.

Hierarchy

The diclonius race possesses two distinctive tiers in-series: Queens and Silpelits. The primary difference between these types is that one can reproduce and the other cannot.

Those that can't breed are called Silpelits. Referred to as "worker bees," they use their vectors to infect Humans with the Diclonius genetic virus on and turn these children into Silpelits when they are born. Silpelits age much faster than humans, with their bodies looking twice as old as their chronological age.

The Queen type, of which Lucy is presently the only member, can reproduce sexually. Additionally, they age like normal humans. While in the anime it was said that there were other mutant children born like Lucy but Lucy was the only stable one to survive after birth/infancy and be able to reproduce, in the manga, it is made clear Lucy was the first ever Diclonius and the origin of the only fertile caste originate from the mutated ovaries of her mother.

There are no male Diclonii in the series aside from Lucy's half-brother. Since he was not a Silpelit, was capable of reproduction, and male, it's unclear if he would count as a Queen/King/Monarch or another new sort entirely. Following the analogy to bees, a likely name for his caste could be Drone.

Destructive Instincts

It is said by some in-story that God chose the Diclonii as the new Humanity, born with the drive to destroy the Human race and repopulate the world. In the final episode of the anime, Lucy tells Kouta that she was born to kill Humans, an idea cemented by her third personality born from the supposed instinct to kill Humans all Diclonii are said to have. However, Nana's character, as well as the incidents surrounding Lucy’s past and relations with Kouta, suggests that it is possible for Diclonii to have empathy towards Humans and that their sadistic characteristics develop as a result of their interactions with the world. Barbara, a clone of Mariko, claimed to have also heard this voice, but hers was a personality shaped by birth and life in a lab. Nana once seemed to sense it but at that time was in shock from leaving Kurama, taunted by Bando as to her lack of a place in the world.

The homicidal tendencies are possibly a result of an unstable psyche, itself a result of congenital recessive mutations, aggravated to such high levels by inhumane treatment from Humans. Through the run of the series, the question arises to the audience of whether the Diclonii's homicidal tendencies are an innate drive to eradicate Humans, or if, like any "normal" Human child, they develop this drive in response to years of trauma and abuse. Their destructive behavior is only ever directed towards ordinary Humans, as they behave benevolently towards animals. This split is possibly exemplified in the anime when a young Diclonius is shown killing a Human for laughing at her, but when the Human's dog bites her hand, she reacts by crying instead of harming the dog. However, the anecdote mentioned above is only in the anime in a story told by Professor Kakuzawa, whose trustworthiness is questionable at best.

Humanity's threat

Diclonius children suffer massive discrimination (infants often euthanized on the spot) by other Humans, and the series makes it unclear whether the often murderous hostility Diclonii show as well is innate or the result of the hatred and contempt shown against them.

Researchers at both the Kakuzawa facility and the government-controlled facility believed the Diclonii to be a serious threat to the Human race and kept them in isolation. When Kurama's daughter Mariko is born as a Diclonius, he remembered an incident in which an escaped Silpelit touched him with her vectors. At this point, he realized that this explained his daughter's condition and the sudden surge of Diclonius births. With Diclonii passing on their DNA to humans, the infected parents have horned children, which would gradually lead to the Diclonius race replacing humans as the planet's dominant species. Lucy mentions the danger to the Human race to Kouta in the final episode, stating she could make sure more Diclonii are born than humans in just five years if she put forth the effort.

Anatomy and Physiology in Elfen Lied vs. real-life

In real life, the pineal gland produces a chemical called melatonin, which is involved with circadian rhythms and causes drowsiness. However, the once mysterious pineal gland has been used in science fiction to explain psychic powers dating back to the early 20th century and the works of HP Lovecraft.

Comparison and similarities to other species

The Diclonii have comparisons and similarities to other species. Most notably, elves, as the story itself is meant to be a very loose adaptation of the Elfenlied poem/song. In earlier chapters the horns actually looked liked elf ears as they were meant to. Bees are also another animal they are compared to with their hierarchy being divided by "queens" and silpelits as the "worker bees." In the manga, Diclonii with powerful enough vectors, such as Barbara, can aviate themselves which is another trait bees are known for. Flying is also an ability that is attributed to fairies which are creatures that are often seen as similar to elves with elves sometimes being classified as a type of fairy. Diclonii "replacing" human children with children of their own kind is very similar and symbolic of changeling mythology.

The creatures are also compared to demons, particularly the oni, as they have horns and are seen as debatably "evil" beings. Like the oni, the Diclonii have freakishly powerful human strength in their vectors. A type of yokai known as a kijo is often seen as a female equivalent of an oni and one of the most famous kijo is named Momiji which is a word often used to refer to a type of maple tree, Acer palmatum, and the Diclonius queen's true name, Kaede, means maple. Onis are also said to have horns like an ox. The bullies who torment Lucy call her an "ox" because of her horns and Nyu's name and sound seems to be a pun on "gyuunyuu" the Japanese term for milk, which cows are known for producing. There is even a type of oni ox creature known as the ushi-oni or gyuki (which first letters sounds similar to gyuunyuu) that shares traits already mentioned but has multiple limbs like how Diclonii have multiple arms in vectors and tends to attack people on the beach and Nyu first shows up on the beach and Lucy and Nana fought Bando on the beach. Many oni in folklore had origins as humans and the Diclonii have origins from humans since they are a offshoot of Homo sapiens. Fairies/elves, just like oni, have often been considered demons at some points in time or beings who had a connection to demonic entities. The way the diclonii make more of themselves is like that of a virus which is actually using viruses to produce more of themselves. Viruses in real life can only make more of themselves by infecting a host which causes more viruses to spread, just like how the diclonii use the vector virus to make more diclonii.

Elvish and fae-folk have also had some history of being considered beings responsible for causing diseases and pestilence, and the changeling mythology itself often surrounds and even comes from the ableism and discrimination of diseased, neurodivergent and disabled children, thinking that a fairy caused such things. Similarly onis are associated with spreading disease, plague, chaos and misfortune. Their very name comes from a genus of dinosaurs which according to a quote in the manga, seemed like the reason they were named after them was because of a research error that the actual dinosaur had two horns. At the very least the name of Diclonius translates to “double sprout”, which the dinosaur was named after because of its two distinct sprouting teeth, but can also refer to the Diclonii of Elfen Lied’s actual horns and their constant theme of duality and “two’s” present in the story. There is also thought to be some comparisons to several different gods/deities and religious figures from different cultures.

Contrary to popular belief, they aren't meant to be "cat girls" and were never compared to cats in any way in both versions. Ironically actual cats were never even mentioned or shown in both versions of the story, but rather the animal often considered the “opposites” to them, dogs. While Diclonii don’t seem to take inspiration from dogs, the animal was known to be something close to the Diclonius Queen’s heart and very important to being one of the starting points of her course and journey.

Known Diclonii

Gallery

Trivia

While some fans will give Diclonius the taxonomic ranking of “Homo Diclonius” or “Homo Sapiens Diclonius/Homo Diclonius Sapiens” the only given official name for the species has been Diclonius. The plural “Diclonii” is also fanon as even in plural the species were only referred to as the Diclonius.
- It seems like the plural of Diclonii was adopted in the English dub of the OVA, as it is said by Professor Kakuzawa and the OVA came out after both the anime and manga ended so it seems to be inspired by fans.
A lot of the Diclonii have similarities to the most famous oni, Shuten-dōji, being outcasted at a young age, feared for their powers and orphaned as well as highly intelligent for a young age (due to their rapid aging), he is also considered king of the oni like how Lucy is queen of the Diclonii. Shuten-dōji is known for being alcoholic with his name even meaning “little drunkard” and Nyu’s personality is inspired by how the elf in the Elfen Lied poem hits his head and acts “like a drunken man” at one point.
The Diclonius' vector's supposed weakness to tungsten, when it comes to weaker and normal powered ones at least, is similar to how fairies are weak against iron.
Elves in some forms of fiction are sometimes depicted as a species similar to or some kind of related species to humans or even a subspecies of them. Depending on the fictional universe elves or elf-like beings may even be a stand in for humans. This is of course, similar to how the Diclonii are an elf inspired race that are an offshoot of Homo sapiens sapiens.
While in modern media typical or “normal” elves are more commonly depicted as either benevolent or neutral with their “evil”, more morally grey or “darker” counterparts being the appropriately named dark elves. In original Norse/Germanic mythology, it was dwarves who acted as the “dark” or even “evil” counterpart to elves however there is some debate and questioning if dwarves were also referred to as dark elves or “black elves” in some old translations as it is unclear. Nowadays dwarves are more often seen as separate unrelated beings to elves and dark elves but who may still be part of the fairy category. By modern standards the Diclonius may be viewed as a sort of “sci-fi dark elf” or a “sci-fi dwarf” if you go by Old Norse mythology.
- Of course there is also the notable condition known as Dwarfism, a naming choice which is more focused on size but coincidentally also goes well with the common theme of ableism and discrimination present in dwarf/elf/fairy folklore that would later inspire Elfen Lied.
It seems possible, yet unconfirmed, that all Diclonius might be plural. It is indicated that they all possess a DNA voice, via what happens and shown with Nana and Barbara however it is never seen how it looks in their minds, it may be possible they all obtain or have a latent “Nyu”-type of headmate as shown with Nyu and Mariko and the clones’ “Myu” headmates. However all scenarios of the Nyu/Myu personalities have shown to only emerge from some sort of head trauma or brain damage and seems like it could only be the result of external factors rather than internal/ingrained ones like the DNA Voice, which, while ambiguous in the anime, the manga makes it pretty clear by its end of how it treats the Diclonius that it’s the result of natural instinct.
There has been some speculation that Lucy and Nana’s hair colors may be inspired by the red and purple leaves of some Japanese maple trees but this could also be coincidental as Mariko has yellow hair, but there are also leaves that turn yellow. This would at least make sense given the maple theme.
While in the manga it is made clear Lucy was to first ever Diclonius to even happen, in the anime there were actually said to be other “mutant children” with the same condition as Lucy who were born before but Lucy was the first one who was said to be “stable” with (most) others dying at birth and Lucy being the only living one ever who can reproduce.
- It is questionable though how the Kakuzawas, who are clearly older than Lucy, were also stable living, presumably real, Diclonius like her, as well as the fact they can reproduce, but in all fairness the manga was barely finished when the anime was made so the people behind it had no ideas where the story was heading with that or what plot twists would eventually unfold.
Despite it not actually being the case, there have been some fans who speculate the Diclonii have some ancient to even prehistoric ancestor that descended into them or that there was some latent gene or other condition that produced them that remained hidden, recessive or uncommon for a while and then finally started emerging again with those like Lucy. Some fans have made their own fan creations of Diclonius ancestors and proto-Diclonii. One notable example of this is a fan character named Lost Number who was meant to serve as a missing link for the Diclonius and has shadowy vectors instead of invisible ones. It should be noted that the concept for a “missing link” itself is also a scientific misconception.
- The idea of a somewhat latent gene that can be found in Homo sapiens sapiens that can produce another separate and super-powered species of humanity is basically one of the main concepts of X-Men.
While the story doesn’t state anything about the Diclonius having anything outside of an Earth born origin, there are some fans who believe that the Diclonius, or what causes its mutation, have some kind of alien or extraterrestrial origins. Funny enough this is exactly the concept for the Witches and other non-human species in Elfen Lied’s spiritual successor, Brynhildr in the Darkness. But rather than being a natural species like the Diclonii they are artificially created by alien parasites, known as Drassils, being inserted into a resurrected human body in an implanted device.
- Even with their rarity, it seems very far-fetched how the scientists and government could keep the Diclonius so secretive and contained in such a way that it seems to be a very big plot hole or suspension of belief in itself. Explained in much more detailed on the reasons why in the narrative gaps page. While it is unknown if the intention was an actual “fix” or just a way to be different in the successor story on Lynn Okamoto’s part, the witches in Brynhildr in the Darkness seem to actually fix this issue by having it so their species is entirely of lab made creation rather than some natural phenomena that is debatably caused by some God who may or not actually exist in the story. It also explains how they can keep them so well contained (for the most part as many escape due to a car transporting them breaking down) as the very thing that gives them their power, their Harnessed (clearly modeled after Diclonius mind control devices), also heavily limits them as it is a device that the scientists can control and can remotely determine whether to limit them, remove their power temporarily or play with their life or death. To add to this, the witches need to constantly take pills every 30 hours to keep themselves from dying. Whatever the reason, Lynn managed to put more sensible limits on the witches that explains better why they are kept such a contained secret compared to the Diclonii.
While the anime keeps things more ambiguous about if the Diclonii’s destructive instincts is more the result of nature or nurture, the manga flip-flops on the reason for their existence and instincts until by the end of the story it makes it so that the Diclonius need to be eradicated as the species and their vectors weren’t made just to kill and replace humans but to destroy the entire world.
- Awkwardly, even after the manga story makes it clear that the Diclonius should and “deserve” to be extinct and just can’t ever coexist with life on Earth, as they are meant to destroy the planet, the twin reincarnations of Lucy and Nyu are meant to be ambiguous in species to leave it up to the viewer if they are now human girls or Diclonii who managed to coexist with humanity and life.
It is unknown why the Diclonius were all given pink hair and red to pink eyes in the anime. A common theory is that it was meant to make them seem even more alien than non-Diclonii humans. However, it debatably might not even be an actual feature of Diclonii in the anime and just a stylistic choice, as it is not actually ever mentioned or pointed out in the anime series itself as a distinct trait of the species, but the case of it just being a stylistic choice or not is also unconfirmed.
- Some old anime concept art depicts Nyu with green eyes, but this is the only (known) early anime concept art that depicts a character with manga colors so what the other characters could have looked like or why this was scrapped is unknown.
- Another theory some fans had was that the reason for Diclonii in the anime to have such similar colors is because they are the “children” or “clones” of Lucy and thus should have her DNA and similar features, however Lucy isn’t the actual mother of Diclonii as she just gives their real biological parents a disease that makes their children born with the condition. Functionally, it would be more closer to the equivalent of some monster, like a vampire, werewolf or zombie, biting a human but instead of that human turning into the monster it would be the human’s children being born with the conversion pathogen.
- While some viewers may find it confusing to tell the Diclonii apart because of it, even with the different shades and hues of pink and red, there has also been some trouble with viewers telling them apart in the black-and-white manga and even some human characters. This could just be more of a result of the same-face syndrome and extremely similar looking characters in the art style that the series had and how it’s one of the anime/manga series that gives all characters a realistic hairstyle rather than a more crazy, distinctly-shaped or exaggerated one you often see in other anime.
- An even rarer criticism and/or opinion from some viewers is that they wish the horns of the Diclonii were more varied instead, with some fans creating their own different horn variants of the species. Ironically despite the fact horns play a more integral and important role in the species biology than hair and eyes, more in depth discussions about the horns are less common or may go unnoticed. There is a part in the later half of the manga where Lucy/Nyu gain larger horns (after Nyu gains vectors) until they break again and go back to normal size. So while it is shown that Diclonii horns can grow into a different size it is unknown how diverse they can truly get.
  - Even more ironic, while the distinct shape of Diclonius horns is directly shown in things like scans showing their anatomy and all, for the most part; the shape of their horns technically doesn’t have any relevancy in the actual story itself other than referencing their elf inspiration. While the size of it may be more relevant in the sense of how they can easily cover them with hats and bows without having them stick or pop out, if one were to redesign the shape of the horns some had or use larger hats as coverings for larger horns, it wouldn’t majorly effect the story. So for the most part, a fan could recreate the same scenes where the Diclonius have any kind of horns, and as long as they don’t do something like cover larger horns by something too small when they are meant to be covered or something similar, they can effectively have the same story writing wise.
While most know that the Diclonii have actual horns but erroneously think they are meant to look or be based on cat/neko ears, there has been a weird Mandela effect among non-fans of the series, usually those who are super casual viewers or those who haven’t watched the series in a long time, that the Diclonii have actual cat ears and are really meant to be cat girls despite that, no matter what, the “ears” are always called horns.
Some people incorrectly call the Diclonius and their powers “magic” or say that they have a source in magic. This misconception might either stem from people labeling anything supernatural as magic, despite that not always being the case, and/or how Lucy/Kaede incorrectly called her abilities magic. Kaede’s claim wasn’t meant to be some sort of plot exposition as it was meant to be a part of how she is an uneducated girl who lacks knowledge on her origins and how it was sad that she didn’t even know what she is until she was taken to the lab facility.
Early manga concept art of the body of Lucy/Nyu/Kaede was going to depict them with light brown hair, similar to Yuka. It is unknown how this would have affected the anime’s choice of giving all the Diclonius different shades of the same hair color if this idea went through.
There is a real life condition that gives humans horns, it is called Cutaneous horns and can grow on different parts of the body. They are made out of keratin rather than bone. There are other conditions that can give people horn-like protrusions from mutated or malformed bones, similar to the Kakuzawas. Ironically, true horns in naturally horned species are made out of both keratin and bone.
There is a condition in nature called erythrism which gives animals a reddish, orange or pinkish hue in nature. In humans this simply manifests as being red headed/ginger. It is also possible for even humans to get red/reddish eyes through albinism. Perhaps a mutation that would evolve for the anime colors of Diclonius (if their colors are meant to be really there that is) would be some weird cross between albinism and erythrism or some other factor.