I don't think that Satan was in Yukio this whole time. Probably as soon as Toudou began twisting his thoughts a small crack in his heart formed, and Yukio began to dwell and obsess. The weakness in his heart has been fully realized, and so that allowed Satan to come all the way through in the same way Fujimoto was possessed. But what will be the point that Satan fully possesses Yukio? Probably after Rin has been "sacrificed."
I do think something else. I think that if there was a "crack" moment in Yukio it started from around
here. Notice how this is connected to Yukio remembering about
Shura's words. Let's take into consideration
Todo's statement. "Hating yourself is the first step to becoming a demon". Yukio verbally admitted he hates himself later, during his fight with Todo, but I'm sure it was already thinking it back when he was remembering Shura's words.
Someone labeled Yukio's hearing noises like they were coming from very far as PTSD. But I think after chapter 93 happenings it's safe to assume that was not -completely- the case. Oc, I do think Yukio was experiencing a PTSD symptom TOO. However, we now have proof that Satan (?)'s -possession- is not only about his eyes, but even his own mind (his memories, prolly his senses, and so on). So, like, mind CAN -control- senses. And I think the moment Yukio started hearing those noises as they were coming from very far may be considered a first sign of Satan (?) trying for the first time to "establish" that connection with Yukio, taking advantage of the very first moment he started to run an in-deep analysis of himself resulting in his realization about his hate toward himself. And the moment Yukio realized that, as Todo said, the first step was taken.
Either this or is this:
"The most important thing is to not suppress one's true feelings." and
"Cause demons will take advantage of that pent-up anger and stress". In this case, Yukio's hearing noises as they were coming from far away was INDEED the first symptom of a "blooming" PTSD and, as a result, Satan (?) took advantage of this to try to establish for the first time a connection with him.
Huh, I don't like how I explained this but if someone got what I mean, pls, back me up. And if I messed, pls correct me.
Lucifer knows something of the power. He said as much to Yukio, but what and what's his motive if he was already going to provide a vessel for Satan through the use of the Immortal type demons?
This is why it bothers me to read people stating "Lucifer is gonna use Yukio to make it a Satan's vessel", "Yukio will be Satan's vessel", etc., I think people are so stuck in the anime they only consider that and forget about the manga.
I hardly see people bringing this up, so I'm gonna put all the points together here. What the manga suggested so far, is that Lucifer is trying to revive Satan by creating a body using the Immortal type demons as materials. A body capable to be possessed by the strongest of the demons, so indeed it needs to be a strong one and with a high regenerative factor so to not decay and last.
What I think Lucifer's plan consists of are these two steps:
- gather Immortal type demons to have his scientists create a body;
- use the "chosen ones"'s DNA to make it capable to sustain Satan's possession.
Why? It's simple. The "chosen ones" (like Todo) are humans who have shown good capability to force demons to possess them, sustain them and eventually control them to the point they literally become one with them. "Chosen ones" is quite a good way to define them, imo. We know that some humans tried to force demons to possess them but failed (unknown woman/Impure Princess. Also, notice that when Angel asked her why she did revive the Impure Princess, she literally said "I became one with the Impure Princess"). Others, like Todo, succeed. So these humans are the "chosen ones".
All we know is that the "chosen ones" are somehow "needed" -during the process- to prepare Satan's body. But not TO PREPARE the body itself. Lucifer said: "It may become necessary to prepare Father's body with the materials we already have (and I'm quite positive he's referring to the large amount of Immortal type demons in front of him)... That is WHEN I need you chosen ones." So the "chosen ones" serve another purpose but we still don't know which. So my guess is that since their DNA proved to be capable to
force a demon to possess their body,
sustain it and eventually
control it, Lucifer plans to use their DNA or something like that to "implant" it in the body and make it capable to sustain Satan's possession.
Now, considering all this, what I think it's pretty clear is that Lucifer is absolutely NOT after Yukio BECAUSE he wants to use him as VESSEL material. He's after the Immortal type demons for that.
But I'm guessing Lucifer considers Yukio nothing different than another "chosen one" and that he wants to "save him" for that purpose, the same as the chosen ones'. That's why he has no rush over getting Yukio by the Illuminati side and none of his men try to put any pressure on him. After all, Satan's not gonna be revived till
around October, and we're in January. Oc, I think this is ONE reason but there may be more.
There's also simply no rush because Yukio is NOT essential to PREPARE Satan's vessel at all. He's not NEEDED at all for THAT purpose. He MAY be needed as a "chosen one" though, so he's gonna be needed later, since the body itself is still not ready (for all we know, they may still be looking for other Immortals type demons behind the scenes, so, if that's the case, then they're still at the "gathering ingredients" stage).
The reason I think Yukio is another "chosen one". Well, simple. He's a human whose "body" (or precisely, his eyes) -seems- to be capable to sustain "possession" from a demon (Satan (?)). If he's capable to sustain possession, it prolly means that he was -forced- in the past to be possessed by that demon (that's why I think his eyes/his eye were/was "transplanted" into him somehow). Demon eaters ate demons. Yukio most likely didn't "eat" a demon, so it's possible someone "forced" it into him some other way.
What I think Yukio's lacking is the last step: to "control" the demon. Yeah, he can get it to manifest while putting his life in danger. What if the reason the demon shows up only this way is because it CAN'T manifest "freely" at any time? My idea, unless there's another reason behind the demon showing itself ONLY to protect Yukio from death, is that Yukio lacks something like a "training". I also think this because I find it weird that the demon tried to speak to Yukio ONLY now. The way it started too. That first small speech bubble with an unreadable font. The first impression I got is that the demon was "testing" for the first time its ability to communicate with Yukio, and it became clearer and clearer as Yukio slowly fell into despair.
Now, this is totally crack theory, but I think what Lucifer is offering Yukio, that "potential", could be something related to Yukio's capability to "control" the demon. Maybe if Yukio knew about HOW he got his eyes/eye when he was a newborn and WHOSE eyes/eye are those/that ("the secret behind your birth") that could help him "control" them and the demon "inside" them. Don't know how, but I think there's a connection.
Why didn't Lucifer know anything about Yukio before Toudou noticed something? If Lucifer supposedly knew some "secret" about Yukio all along, why did he seem surprised? Why is he in no hurry to recruit Yukio, or is proceeding with his plans as if Yukio wasn't a factor all along? Maybe it's because Lucifer knows jack shit. Either that, or he doesn't know enough to make anything of it. All he knows is that there's -some- strange power behind his eyes, since Toudou noticed it and he saw some of it himself. We can even call shit on the whole "secret behind his birth" because as far as we know, the entire thing was kept a secret, even from the Order.
I have this theory that I mentioned somewhere else too that Yukio was experimented on when he was a newborn. Either to be transplanted someone else's eyes or for some other reason. The moment the twins were born, Rin was half-demon. Ok, but Yukio was the son of a demon who didn't inherit the power. He may somehow have inherited the recessive gene of that power. In any case, I can see the S13 scientists considering him good experimental material. If that's the case, I have the feeling they tried to do something to Yukio but, at first, they didn't get any result. So they thought the experiment was a failure and the question ended there. 15 years later, the results are starting to manifest. Todo clearly knows something about it and prolly he knew that the experiment was a failure too. But, surprisingly, Yukio's eyes/eye awoke and he recognized them/it.
Lucifer prolly knew something about an experiment on Yukio but not the details. So he had to see Yukio in person to verify what kinda experiment could be. And from here on I'm lost... So, hehe. Before I venture any further I stop here! I have too many ideas but can't find a way to express them properly/connect them. *sigh* We need more infos!
