Mikaela Hyakuya's Demon

Mikaela Hyakuya's Demon refers to the Yu, Akane and other children that Mika interacted with when he was raised into the air after extensive blood loss. Rather than an afterlife location or a memory event that Mika awoke in, the humans collectively and the world itself is treated as a creature, one that behaves like a demon.

Appearance
It appears as children from a time setting where the buildings and surrounding landscape have not been ruined by the apocalypse event. Yu is wearing casual clothing including a darkish T-shirt with a darker neckline and a small star design with some text above it over the chest area. This is as well as light shorts and socks reaching his shins within laced shoes. Akane wears a dungarees style skirt over a T-shirt and other children wear similar summer themed clothing.

Personality
In stark contrast to other demons which rely heavily on guilt and fear to possess their hosts, this demon was both very kind as well as comforting.

The demon acted largely as how Yu, Akane and other children themselves likely would have behaved given the settings. As Yu around Mika it maintained the pleasant illusion by having Yu tend to activities such as eating and bathing where he appeared happy all the while. Not once did the demon have the appearance of Mika’s family speak anything malevolent. If to gauge how aware Mika was of the situation or if it were mimicking Yu’s attentiveness to Mika, the demon was mindful of Mika’s body language and asked him what was wrong more than once.

During its act as Yu if the demon were picking up on what he would have said or they were its own feelings, the demon insisted that he did not cry. It raises whether he had to be the mom when Mika stated Yu was like the mom of their whole family. It made some comments that could be deemed childish that Yu might have made such as mentioning push-ups as a means of solving problems. After mentioning that it was alone for “a really, really long time” the demon echoes what Yu said about not feeling alone anymore since he has Mika and raised the matter that it was indeed possible for it as Yu and Mika to actually be together for a thousand years.

In a departure from observable demon behaviour it had Akane mention demons early on. With Mika aware that it is a dream and saying as such, the demon does not falter or amend its practice even with the suspension of disbelief gone. Ultimately rather than not address the subject or use deception it attempted to normalize the circumstances so that by the end the demon was asking Mika as a close one to willingly choose to become a demon by providing dreams better than reality. Aside from methods, notable personality details were displayed. After a joke that Yu used to cry, and then Mika addressing him as papa the demon may very have had its only genuine reaction which was decidedly not a pleasant one. Additional traits was that the demon repeatedly commented how tired it was on five occasions. It apparently did not rest whilst Mika slept and after it stated it was tired the demon still partook in activities. It postponed sleep to bathe instead and after yawning it resumed speaking to Mika when he wanted to talk. Another area was its notion of time. Acting on a longer timescale the demon thought sleeping for two hours in a field as others played and being together for years longer than a human lifespan was nothing out of the ordinary.

History
It is unknown where this being would have came from. Mika himself was the one turning into a Black Demon according to Guren Ichinose, after being injected with a serum by him when Mika was being attacked by Guren along with the spirit of Mahiru Hīragi, and Noya Hienma. After the fight Mika rose up into the air where this independent consciousness was ready with a world and illusions of family for Mika to wake up in.

Post-Shibuya Arc
The demon appears as young Yūichirō Hyakuya and is sat beside young Mikaela Hyakuya in a field of grass with a cloudy sky above. It asks Mika what is wrong then clarifying why he is asking, the demon comments that Mika was drooling whilst he slept. Reasoning that it was because they were up late playing Othello together last night, the demon states that it is real sleepy too. Offering its hand to Mika, the demon says for them to head home where if they take too long the kids will start whining that they are starving.

Nearby to the suspension transmission towers where they stand, Akane Hyakuya is playing ball with some other children. This Akane teases that it is a child’s fault for being too slow and if they do not run fast enough she will tag them with the ball and turn them all into demons. With Mika picking up on the demon word, as Yu it asks Mika what is wrong. When he mentions a nightmare the demon wonders what was it about and whether monsters chased him. It plays along with Mika, questioning whether they were zombies with hand gestures to match. Voicing that ghosts are the scariest, the demon says that Mika had better not wet the bed tonight thinking about it. It adds that Mika should not seriously wet Yu’s bed.

Other children are happy when Mika calls that they are going home to have curry. In addition, the demon presents a light-hearted exchange of Yu saying that he prepared the curry and how cutting the potatoes that he actually did as the most important part. Furthermore Akane joins in the scepticism of Yu’s claim and then speaks to Mika that it is about time that he woke up. Akane states that Mika was asleep for two hours, and Yu stretches as he repeats that he is super sleepy. Yu announces he will head straight to bed after dinner and leads the children to get going.

Yu and Akane are holding hands with the children as they happily make their way back. By nightfall, food is being prepared in a building resembling the Hyakuya Orphanage where on the inside there is a carpet addition under the table. Yu directs everyone to sit down and for them all to say thanks for the food and looks eagerly at the curry even when Mika has his eyes closed.

As Yu gobbles the curry, the demon appears perplexed when Mika questions Yu what happened to the director. It then has Yu ask Mika what is wrong when he resumes eating without another word. An exchange occurs as another child wants to play cards after dinner, and Yu replies that he was up late last night playing Othello with Mika and is really tired. Despite feeling tired and stating that tonight they are all going to bed early, Yu appears happy bathing and then brushing his teeth around Mika and their family. It maintains that disposition not reacting to Mika looking at Yu. Whilst the family sleeps the demon enters the room as Yu and yawns whilst voicing how tired it is. Tired to death after today. Listening as Mika feels that this is the greatest that everyone is here, the demon guesses so whilst adding that it is super tiring. With Mika regarding Yu’s complaints, the demon listens as Mika describes Yu as being way different than when they first met. Jokingly told that Yu was like a demon in the figure of speech sense who could not be anyone’s friend or family, and that he was crying and whining all the time, the demon listens with a face that may not have been reacting as a child being described comically as a demon, but as a demon whose secret has been discovered. Its reaction was to resume the human behaviour by rolling over and commenting that he did not cry.

Hearing that now he is like the mom of the family, Yu questions why he has to be the mom. With his back to Mika, Yu’s facial expression appears somewhat irked as he tells Mika to “shaddap” after being addressed as papa. The demon resumes listening as Mika speaks of how it is the greatest that they are all together, still alive and healthy. It replies who Mika is calling stupid when he says that Yu is still saying all the stupidest things.

The matter turns to being together happy and growing up. Soon they will be fifteen then twenty and whilst some of them may go their separate ways Mika and Yu will always stick together. When Mika mentions that if they can look back and say they had a full life being nice and considerate, Yu asks Mika what has gotten into him. The demon considers Mika’s spoken feelings of how happy he is right now that he could cry, and decides to follow suit. Saying that it is a good point, the demons shares that it thinks that sometimes too, almost everyday. Confirming that is the case, the demon says it was alone for a really long time but then met everyone. Yu says most importantly he met Mika.

Feeling now it is not alone anymore, the demon says it is sure it is going to come true. What it means is what Mika said, and querying what exactly it was again, the demon raises them living to a hundred together then two hundred. On the latter whilst Mika points out they are only human whom will not live that long, the demon has a childlike exuberance as it insists how it really means it. Grinning happily as Yu, if the whole living together thing is Mika’s greatest happiness then it is sure it will come true.

When Mika is not so sure so the demon is certain it will come true, Yu says that he will make it happen. Continuing, it says if Mika wants it will even make it so they stay just like this for a thousand years together and be the happiest ever. Stating that Mika cannot be sure about not being able to live to a thousand, the demon adds to the other part of the pretence by suggesting that they do a thousand push-ups every day to accomplish it.

The grand promises of being able to live together for extended periods of time beyond a regular human lifespan and the childlike proposal of how to achieve this are placed to one side as Yu takes Mika’s hands into his own. The demon assures Mika that he does not have to be scared anymore. He is here and Yu will be with Mika always. Confirming that he will never leave Mika, the demon as Yu assures him that nobody is going to die because they are all doing push-ups.

At this point the demon turns the conversation to needing Mika to want to be here forever and accept that it is his greatest desire. Not changing the act even with Mika stating it is a dream, the demon hugs Mika as he cries how everybody has died. Reassuring him, Yu says that he is here and will always be so Mika will be fine.

In response to Mika stating that he is tired, the demon answers that is fine, they will still be together for one, then ten thousand years before ending with forever. As the demon explains that this is possible here, from Yu’s hands placed around Mika’s waist there is a black mold appearing substance spreading over Mika’s pyjama top. If Mika really wants it and chooses to become a demon who devours human desires then he will be able to stay here with him. The demon says they will be together inside a world of happiness. That it what Mika wants and the demon as well. The demon is not visible as six seraph like wings appear on Mika’s back.

At some point at night as Yu this demon answers Mika that the other orphans really did not want to go to bed. Replying that he is wide awake now he asks whether Mika is hungry and is happy to state that it is cup noodles time. As the noodles are eaten he does not in any way acknowledge Mikaela stood behind Mika. The building has lights on on the upper and lower floors as he happily eats with chopsticks around Mika. He is shocked at seeing Asuramaru thudding his way into their home and holds Mika's arm as he hears Asuramaru detail how he is going to eat their family and rip their hearts the shreds.

In response to Asuramaru the demon as Yu shouts for Mika to run. Pushed outside the room he steadies himself before calling Mika out of concern. Instructed to get the kids outside he runs down the corridor. In the sleeping area it shouts for others to get up and alerts them that they have to hurry and run. With Asuramaru controlling Mika, the demon may have sensed and literally seen his horned silhouette approach with a knife. Regardless he appears happy to see Mika there, before Yu's expression changes as Mika raises the knife. While Mika cannot control his body, the demon, or Asuramaru's illusion has the orphans lay silent as Mika stabs into them. The illusionary Yu offers no resistance aside from asking Mika to stop this. His shock at being stabbed in the chest changes to anger as he states that this if Mika's fault and that he did this, which is what Asuramaru felt was both Mika's deepest fear and desire.

Powers and Abilities
Like demons it could create an illusionary environment from the world to people inhabiting it. It added past aspects such as a game being played the night before and food being prepared at some point of which Mika accepts the latter.

Able to access memories, it could use visions to physically and mentally replicate humans down to their childhood appearances and personalities. Whether it used those most important to Mika which were fellow children, the demon appeared unsure when asked what happened to the director and no other adults were shown.

Mikaela Hyakuya
Although the demon voiced how it was tiring with everything, it went to great lengths to provide a world for Mika with his family happy around him. It consistently remained as Yu in its speaking and was attentive to Mika’s worries. This included hugging Mika and saying that they would always be together. It reassured Mika when he was upset that Yu would always be here. In context this manipulation was not to possess Mika but to turn him into a demon, and even with that awareness it continued to freely share that Mika becoming a demon was the way to remain in the perfect world. With them threatened the demon as Yu told Mika to run before heading to save the other children as Mika said to do.

Yuichiro Hyakuya
The demon acted just like Yu and drew more upon his actions that would be deemed affectionately stupid as well as displays of tenderness for Mika. Ultimately what the demon knew of Yu was only useful in appearing as him for Mika to feel at ease in becoming a demon himself. If the comments related to feeling alone was the case for the demon then it and Yu shared that feeling of loneliness.

Akane Hyakuya
As Akane the demon depicted her as someone entertaining other children as she took part in a ball game. Whether the demon knew much about her compared to Yu or not, Akane was used to state some comments that were rather odd given the circumstances. It saw nothing suspicious with having Akane mention that Mika had been asleep there for around two hours, and also have her mention demons which would hint to the situation. The demon may have thought Akane would say such things or used her as a different type of prod for Mika.

Mikaela
The world this demon acts in is to be sustained by the child of Sika Madu who has entered the world as a demon. If this demon knows Mikaela means to support where they are since Yu and Mika are seen as precious, or if he even knows Mikaela was there observing them this demon does not show it.

Asuramaru
Yu's black demon bound to his cursed gear sword. As Yu himself his appearance is not commented on although he does express shock at this other demon's arrival and extremely hostile intent. He, or an illusion of a young Yu created by Asuramaru, would be stabbed by Mika who was being controlled by him.

Quotes

 * “Well, we were up super late last night playing Othello together.” – Giving a reason as to why Mika was sleeping and the choice of game the demon decided that it and Mika played.3
 * “Heh heh! That’s your fault for being too slow. If you don’t run fast I’ll tag you with the ball and turn you all into demons!” – The first time having Akane talk, the demon saw fit to have her speak like this whilst balancing a ball on Akane’s finger. As if to further hint itself that something was amiss the demon also had Akane bring up demons to begin with.5
 * “Ghosts?! Those are the scariest!” – If they are Yu’s or the demon’s fears, or a comment to maintain the conversation, demons themselves have ghost like qualities.8
 * “It’s about time you woke up, Mika. You were asleep for what had to be two hours.” – Having a concept of time, Akane may have been used to speak that it is about time that Mika woke up from his sleep on the grass, or that he wake up from the dream that he is in at that moment. Neither ‘Akane’ or ‘Yu’ saw anything out of the ordinary in Mika apparently sleeping upright and for two hours whilst Akane and the other children played. If either Yu or Akane were real this would have been a clue that something was not quite right if they thought like the everyday person. The demon may see this as normal behaviour or not be familiar with time lengths.9
 * “Good point. I think that sometimes too. Almost every day.” – With Mika voicing how happy he is, so happy that he could cry, the demon has Yu speak in agreement. With Mika joining it recently the demon may have felt that way before, alternatively the second and third or all parts of the statement may have been said to further the emotional connection to Mika as the demon prods him along the path to becoming a demon himself.
 * “I mean, I was alone for a really, really long time.” – Through some means the demon may be aware of Yu’s feelings of how Yu felt alone for eight years even around his parents before he met Mika, or the demon is speaking that it itself is also saying it is genuinely happy after being alone for an undefined long period of time.
 * “So I’m sure it’s going to come true. What you said. What was it again…? We’ll turn a hundred together, then 200. That thing.” – Whilst it could be a convincing display of what a young person Yu would say in this scenario when clarifying how a conversation went, it could also be the demon steering the conversation to spending long periods of time together with Mika. Mika’s exact words regarded them growing up listed 50 as an age, then by a hundred they would likely be dead before the discussion turned how they would fondly look back on their life. The demon may not have really been listening to that, in any case it disregards human’s mortality and mentions a drastically higher time of 200 at which point it begins listing longer amounts of time it and Mika could spend together. (In terms of the manga itself the dialogue also uses the words “one hundred” yet the number “200” for the two numbers of years).
 * “It will! I’ll make it happen. If you want, I’ll even make it so we stay just like this for a thousand years! Together and the happiest ever!” – Whilst Mika is seemingly under the impression that this is a topic that Yu as a person has not really been thinking seriously about, on the surface, it is a demon talking who is promising the impossible and truly has the means to deliver it. Those familiar with demons and taking the words literally could regard such speech as an indicator of what the Yu really is.
 * “You don’t hafta (sic) to be scared anymore. I’m here. I’ll be with you always.” – As Yu holds Mika’s hands the demon speaks of Mika’s inner fears that he has not outwardly shown and comforts him.
 * “Heck no! Cuz (sic) we’re all doing push-ups!” – Replying to Mika that nobody is going to die. Based on observed actions whilst the real Yu would think of combative ways of ensuring that no one would die, rather than anything stern the demon taps into Yu’s side that can make what others view as not intelligent remarks. This front in the face of Mika commenting that stupid Yu strikes again and that everything cannot be solved with push-ups is also used by the demon to lead Mika where the demon desires him. Playing as ‘stupid Yu’ made it more believable to Mika and so easier to manipulate.
 * “C’mon. Want it. Please. Want to be here forever. Accept that it’s your greatest desire.” – A compelling illusion and a show of wondrous interactions leading to the moment. Yu’s face appears expectant and the words reveal what the demon wants Mika to say.
 * “It’s okay, Mika. I’m here. I’ll always be here. So you’ll be fine.” – Hugging Mika as he cries, the demon knows how to make him feel better.
 * “We’ll still be together. For a thousand years. Ten thousand years. No… Forever. That’s possible here. If you really want it… If you choose to become a demon who devours humans desires…” – The build-up of kindness reaches its true point, the demon offers Mika eternity with ‘Yu’. An end result to turn someone into something to devour human desires is something sought. The demon knows what is possible in this realm wherever it may be. As a close one offering it, the choice to become a demon is apparently something done willingly yet as the demon speaks this it uses Yu’s hands to cause shadows to cover Mika’s clothes where he is holding him. It may not need verbal confirmation or was going through with the process regardless of Mika’s answer.33
 * “… You’ll be able to stay here with me. We’ll be together inside a world of happiness. That’s what you want… …And what I want too.” – Staying with Yu, inside their world of happiness is something the demon knows Mika wants, and whether it is Yu’s thoughts, the demons, or a comforting lie, the demon states it wants the same.34

Trivia

 * In terms of origin and setting the cover image for Chapter 93 depicts a section of the universe where Mika is sleeping.