Yu (Homunculus)

Yu is the named given to a homunculus by Mikaela, where both are characters in the world of the Seraph of the End series. Existing in the prehistoric past, Yu the homunculus was around with Mikaela during the era when dinosaurs roamed the Earth where they were seen in a seraph civilization. This specific homunculus would come to work very closely with Sika Madu for his seraph resurrection based plans.

Appearance
The most distinct feature about it was the single large eye in the centre of its being, which is its main means of expressing emotions. While the sclera was white, both the pupil and iris were dark in coloration. Additionally, it was a spherical based entity. Capable of appearing in a smoke like form, as well as from from a black circle seemingly into Space, like other homunculus it could also appear as a more solid ball.

For what its skin was made of, it was dark in coloration but able to reflect light and refract it in parts. Able to expand dramatically in size, the homunculus could appear to become as large a moon. From its body, multiple long thin tendrils split at the end like fingers could be used to dextrously interact with various objects at the same time.

In sustaining damage, the homunculus could be blasted completely apart. Tears similar to a burst balloon may indicate a hollowness to its being. Able to exist in some unseen state despite its apparent destruction, upon darkness being made the homunculus could materialize in a form remarkably similar to a black sun. Before appearing in a misshapen circle form with a specks of light emanating from a bight core, the homunculus could become its regular state once more.

Upon passing objects such as a coffin out its body, an opening could appear out of the homunculus' lower section to allow this. Expelling something such as a wholly developed human child left the homunculus appearing ruptured at its based. Parts of it seemed to drip in an indication of the fluid like component to its being.

Personality
Partaking in a game of hide-and-seek, Yu the homunculus awaited Mikaela to find it as it hid inside a living lizard. Apparently excited, it communicated this non-verbally by bouncing around before Mikaela. Its interest in what others are saying is shown by maintaining its gaze at them.

Sentient and also able to read basic and advanced words, the homunculus had also apparently read information that Sika Madu was hiding from Mikaela. For all the exceptionally sensitive information Yu has access to, it does not reveal it to others right away, if ever. The same applies for when it can seemingly make out that Yu and Mika are in the area. When it outright can see Yu and Mika within a memory it makes no mention of this to Sika Madu who is alive in the present time and who can also access past memories.

Not forthright in answering Sika Madu whether it had saw everything he experienced, the homunculus' actions are a means of communication. Asked perhaps rhetorically how Sika Madu is to collect the power he needs for resurrection, the homunculus responded by having the coffin of Mikaela slide out of it as the correct answer.

Very efficient, the homunculus is ready at once to carry out orders without any delay. Tasked with darkening rings of light, the homunculus blasted its way upwards to begin right away. When cursed dolls needed to be made, the homunculus generated multiple humans.

History
Although not seen, Yu the homunculi was hidden inside a small lizard amongst some trees. Upon being found by Mikaela, the homunculus flew out the lizard's mouth when it was opened. Animated, it bounced around in apparent excitement while Mikaela stated he knew right away where it was hiding. When Mikaela spoke for it to come since father was calling, the homunculus was on his shoulder and flown towards a smoking mountain in the distance.

Within the seraph civilisation, Yu is levitating beside Mikaela with its gaze fixed on the ice cream he is carrying. Rather than placing itself on his shoulder, this time Yu flies upwards with him through the air. They both make their way to an opening in the side of the very tall and thin building rising from the seraph civilisation far up into the sky. While doing this, Yu is looking ahead to their destination.

At the reported top floor of the Tower of Babel, the homunculus floats slightly above Mikaela as he greets his father Sika Madu. Ever-silent as they speak, the homunculus physically reacts to being spoken to by Sika Madu after hearing that it was told by him to keep an eye on Mikaela. Its name mentioned by Sika Madu, it is close to Mikaela who is joyful that it has been given the name Yu and takes to looking at him. From Yu the homunculus' perspective it regards Mikaela's happy expression.

Observing Sika Madu as he details that naming a thing could curse them with a heart, it appears to listen further as Mikaela hears he was named by his father to curse him. While Mikaela has taken to embracing Sika Madu and seeks to clarify that he is joking, Yu the homunculus' gaze turns to something else. To the side, the homunculus is able to discern that Yu and Mika are present in this scenario.

After Mikaela has fallen ill, the homunculus looks at him as he kneels on the floor. It watches both Sika Madu and Mikaela as they discuss how they would each feel upset at the current situation of illness. It draws closer to Mikaela when he is happy to head to the cleansing room and goes there with him.

Within a room at some location, the homunculus floated over and looked in Mikaela's direction as he rested his head on Sika Madu's lap. It maintained its position over the bed they were on as Mikaela and Sika Madu spoke about going outside, and when going on a picnic was mentioned. Its concentration was on them as the discussion took place.

Watching Sika Madu leave the room, the homunculus then looked to Mikaela who was happy to speak about the picnic. When Mikaela said that it should come with them too, the homunculus considered this for a moment before having an expression of uncertainty.

When Paimon entered the room and meant to attack Mikaela with a knife, the homunculus acted first and moved itself in the way. Positioned in between them to protect Mikaela, the homunculus was struck by a light based power from Paimon and sent crashing into the wall.

For what the homunculus' fate was after being struck, whether resurrected or summoned it could be formed out of portal of Space that Mikaela's coffin was lowered into. The circular opening became a spherical ball after Sika Madu spoke for light to hide from God's sight and become darkness. Sounds were involved as the homunculus opened its eye.

Informed at once that Sika Madu was going to resurrect Mikaela and bring everyone back, the homunculus was directed to take all the light in Babel and convert it to darkness. Just as rapidly, the homunculus was able to blast its way out the tower, and propel itself upwards.

Raising itself to Space, the homunculus was before the many floating halos of light around the Tower of Babel. Gazing at one, the homunculus was able to gradually darken the light ring until it became fully black. From its influence, the dark ring then was seen to contain a row of individual eyes that resembled its own. Having grown to a huge size itself from this process, the homunculus was visible from Space to those on Earth such as Amon and Astaroth.

From the now colossally large homunculus were multiple long tendrils that were attaching themselves to the black halos. Where seraphs armed with trumpets had appeared around it, the homunculus looked to their presence. Tending to its duties, the homunculus then found different rings of lights form from the seraphs' trumpets. From a fracture in the dark centre of Space, the homunculus was blasted by a thick beam of light and blown apart.

While apparently destroyed, it is possible the homunculus was able to view a humanoid angel and the seraphs that attacked it go on to destroy the civilization on Earth that it had lived in. Seemingly unable to form for millennia until Sika Madu was able to produce darkness, Yu the homunculus was able to materialize as a light within shadow before taking its form.

Addressed by its Yu name and after being questioned whether it saw everything, the homunculus had a subdued reaction. It took to looking at Sika Madu before he spoke how he could resume his resurrection campaign given he could no longer touch light anymore having become an undead. Asked how the power for resurrection is to be gathered now, the homunculus responded by slowly dropping the coffin containing Mikaela onto the ground.

As its base opens for the task, the homunculus observed before beholding the coffin that lay before it and Sika Madu. The homunculus listened as Sika Madu detailed a plan to resurrect Mikaela to access the light within seven keys he holds in order to resurrect others.

Once Sika Madu decided that copying God was the best way, the homunculus was part of a joint effort to create cursed dolls made out of mud who could collect darkness. Shimmering with light after being physically touched by Sika Madu's hand, the homunculus watched as it somewhat violently expelled a fully formed human child with dark hair from its base.

Whether from Sika Madu's comments on creating humans, or beholding the first one it has made on Earth, the homunculus wobbled with enthusiasm at some matter. It may have been the reaction of a second human in the process of being formed as shortly after the homunculus would eject another youth with light colored hair. The bubbling like base of the homunculus would then produce at least thirteen other children for fifteen in total seen. It dropped them on the grass where the grave markers of angels were within view a short distance away.

As the children registered their new surroundings, the homunculus focused on Sika Madu. Touched by Sika Madu again, the homunculus was directed to make these humans greedy. Having them ephemeral, with melancholy, and strong as well were other features to instil in them. The homunculus was part of a further phase of the plan to place the souls of deceased angels into the humans, then have them breed and prosper to have more to gather darkness.

Where it would appear that the souls of angels had rose up to fly into the human children, the homunculus with Sika Madu was apart from them all as it engaged with him. Engrossed by what Sika Madu was saying, the homunculus did not appear to notice that the first child it created had approached the coffin of Mikaela and could hear from him.

Story
Where Yu and Mika exist in the present time they have established themselves in the Sea of Trees around Mt. Fuji where they mean to access past memories. This memory of the prehistoric past is one able to be accessed. Like them, this particular homunculus appears unique among others of its kind, along with Mikaela and Sika Madu, in that it is able to also detect their existence.

The homunculus' activities, from defending Mikaela from Paimon and producing children, two of who resemble Yu and Mika, are observed by them both. Where the homunculus was seen by them again in the area where it created the first humans seen on Earth it made no indication that it could see Yu and Mika at that point in the memory.

Powers and Abilities
Seemingly having the power of possession, the homunculus could enter and conceal itself within a living being. Its ability to form itself into a shadow based substance likely enables it to conceal itself within a smaller entity such as a lizard. While it could hide itself visually from Mikaela, it did not display the capabilities of being invisible to other senses he had. Naturally airborne, it is presumed that like others the homunculi could carry itself through the air at various heights and distances.

From within its lizard host the homunculi could apparently use it to stare in the direction of something it could see. Its ability to perceive things made it the only being from the prehistoric past to be able to make out that Yu and Mika were within the Tower of Babel with them. Other homunculi in the seraph civilisation did not show this ability to be able to perceive viewers from the far future.

Having the strength to break through a structure such as the Tower of Babel, the homunculus also had the means to blast itself upwards at a tremendous speed and breach Earth's atmosphere. Able to exist in Space, the homunculus could move itself freely there too. For what its body could not endure, the homunculus was split apart by a seraph generated beam of light.

From looking to a ring of light the homunculus could darken it completely. Either from its own input or forming others the ring of now darkness could have eyes resembling its own appear. Extensions from the homunculus could be used to interact with objects namely an amount of shadowy like tendrils that could attach themselves to rings of light. Perhaps absorbing this energy, whatever the case the homunculus could exponentially increase its size to appear as a moon visible from Earth.

Even after being destroyed physically, the homunculus could seemingly reconstitute itself to acquire the coffin of Mikaela a very short time after. Further, it was capable of storing such a large object within its body. Rather than any size affecting abilities being used on others, it likely a portal based ability to transfer objects where it wanted. The homunculus could drop the coffin containing Mikaela without the body being moved from place.

Upon contact with Sika Madu's light-enveloped hand the homunculus was able to produce human children. Whether outright created or transported from another location, the homunculus could rapidly bring a large number of children of different genders and skin tones to establish the first known presence of humans on Earth. Though some non-contact means, but again with Sika Madu's intervention the homunculus seemed capable of installing emotions in humans, namely having them greedy, to granting traits such as melancholy, to making them ephemeral and strong.

Mikaela
Having been tasked with observing the First's son, Yu the homunculus went along with his escapades such as playing hide-and-seek and acquiring ice cream with him. Close to Mikaela, it would rest on his shoulder as they returned home together. Yu the homunculus would focus on the ice cream Mikaela had as well as regard him with a similar apparent fondness. Having been given its named "Yu" by Mikaela, it allowed itself to be handled and squeezed by him. Where Mikaela did not like the cleaning room, Yu went there with him. When Mikaela was assailed by Paimon, it acted to protect the former from attack.

Generated again, the homunculus set about darkening light where it was involved with an attempt to resurrect Mikaela. While it would be attacked before it could carry this out, the homunculus sought out and acquired Mikaela within his coffin and kept it safe from a joint seraph attack that destroyed the seraph civilization. For millennia the homunculus apparently kept Mikaela secure to present him before Sika Madu when he regathered his means to attempt his plan in a different manner.

Sika Madu
At some point, the homunculus had received a directive from who would be the future first progenitor of the vampires. At being spoken to that he was told to keep an eye on Mikaela, the homunculus reacts yet does not look at Sika Madu. Apparently hearing everything the First says to his son and understanding it perhaps better than Mikaela, this homunculus had also apparently read the information the First had tried to conceal.

Brought back into being by Sika Madu and referred to by its Yu name now, the homunculus complied with his orders to commence a resurrection plan. When Sika Madu was able to conjure darkness again, the homunculus formed and may have observed everything Sika Madu endured in the millennia he was cursed alone on Earth. The homunculus was ready to answer how they could resurrect others now by producing the coffin of Mikaela.

The only sentient being around Sika Madu at that point, the homunculus was used to bring forth the first child viewed on Earth. Multiple other children were made in Sika Madu's goal to have them gather darkness for resurrection. Ready to efficiently help with that, the homunculus was seemingly also fine in instilling emotions Sika Madu wanted the humans to have.

Incredibly helpful to Sika Madu for what it had done, and was able to do, the willingness to carry out his directives appears to have formed a natural working rapport between them. It reached the extent where the homunculus was engaging with Sika Madu to the point that neither of them noticed that the deceased Mikaela was communicating with one of the human children nearby.

Yūichirō Hyakuya
Sharing a first abbreviated name, the homunculus could perceive this human member of the Moon Demon Company who lives in the present time and was accessing a memory where it existed in earth's prehistory. While capable of communication, the homunculus neither engages with Yu or informs others that he is there. The first human the homunculus would produce on Earth was a young boy who resembled Yu.

Mikaela Hyakuya
Where Mika was a demon when the homunculus was first seen noticing him, he is someone who physically resembles Mikaela. The homunculus sees but does not act on Mika's presence in the memory. This is all the more striking since as well as being watched by those from the future accessing a memory, the homunculus would have seen Mika's active demon traits such as his horns and tail which were not a sight it may have come across before. It is not clear if the homunculus knew it was looking at what was likely supposed to be a future vessel for Mikaela's soul.

Paimon
When Paimon attempted to murder Mikaela the homunculus did what it could to defend him. If it was outright destroyed by Paimon's light based attack the homunculus could reform later.

Seraphs
As with other homunculus, this one paid no specific mind to cloaked seraphs that it shared a civilization with as it remained near Mikaela. In adhering to Sika Madu's orders, the homunculus acted to try and resurrect the seraphs who had perished from a plague. Due to what it was capable of, the homunculus was tasked with placing angels souls into humans it had just created which it did.

Humans
Millennia after the seraph civilization fell, the homunculus obliged with Sika Madu's attempt to create cursed dolls out of mud and the first human seen on Earth is what ruptured out its base. Accordingly, in creating human children whole or bringing them from another location, this one homunculus appeared responsible for establishing human life on Earth.

The homunculus appeared capable of altering human emotions. It could induce feelings that Sika Madu wanted in humans, namely greed and melancholy. Further, it seemed able to affect humans by having them transitory and strong. Directed to place the fallen angel souls in humans, the homunculus was also resorted to in order to have humans breed and prosper.

Trivia

 * First seen in chapter 123, the shadowy eyeball being would have its species name revealed as a homunculus in chapter 125. Further, this specific homunculus would be named Yu.
 * Not specified whether it is the same, but the eye existing within Yu's memories has also witnessed events Yu can recall.
 * In chapter 129 the homunculus materializes in a form virtually identical to a black sun.