Greetings, thanks to the inevitable exams, this is delayed quite a while.
Without further ado, let us begin. :)
Yushiro was surprisingly tolerant when he let them in. Perhaps the flow of time, along with nearly a millennia of solitude, wore away the sharper edges of his personality. Or perhaps it is the loss of a loved one, which rendered the bristling wall of defenses useless, for there was nobody to defend.
He did not change much in appearance, like any of them. His teal hair was still combed neatly and swept to one side, and he still wore the white haori, though it was doubtful that it was the same from a thousand years ago.
They walked down a corridor with paintings hanging on each side, each framed exquisitely with carved wood. At the end of the hall, they were let into a sparsely, but comfortably furnished room. The host himself took the only armchair in front of the fireplace, leaving his two companions to stand awkwardly.
"Well?" Yushiro demanded, pale lilac eyes darting between them suspiciously.
Gosei, never someone to care for the rules regarding respect or courtesy, as Itaji discovered over the years, perched herself onto a table, ignoring the bulging vein on Yushiro's forehead the action elicited.
"Well…" Gosei shrugged, "do you want the long story or the short one?"
"The short one, please, I don't want to be stuck here until the sun comes up." Yushiro rolled his eyes and crossed his arms. "Start speaking, then."
"You know how literally everyone's got one of these things they call 'Quirks' these days, right?" Gosei's voice was unnaturally light, like she is merely talking about the weather instead of something that may be the end of their freedom as they know it.
"Yes?" Yushiro leaned back on his chair, "go on."
"And you remember the time I sent you this gigantic spiel on how it may be Blood Demon Arts doing the work and proved that demons cannot reproduce-"
"Get to the point."
"The point is-" Gosei paused, "that…" she dragged the word out long, "Oh God damn it." She dug inside a pocket and produced a stack of papers, running a finger along it, she finally stopped at the middle of the second sheet. "There it is. So, Point one: I found a couple of evidences that Quirks are, in fact, some form of a mutated Blood Demon Art of some random unknown origin that I do not know yet, so do not ask, Yushiro." Said demon shut his partially-opened mouth with a scowl. Gosei went on, "I prepared a script for this, with all my points listed out in the best order possible, do you want to hear it?"
"No."
Gosei acknowledged Itaji for the first time since she started talking, "do you, Itaji?"
"I could if it makes you satisfied." Yushiro gave him a death glare.
"Alright, let's start!" Gosei declared, rustling her papers importantly, "so, that was point one, now to point two.
"I went abroad for a while after that little incident I caused with the Yakuza to lay low, and while I was out, I saw a couple of our friends from the Taisho Era. Reincarnated, of course, so they didn't know me. If I were you, Yushiro, I would go to Venice, Italy. There is a female doctor there that you surely may take a fancy in." She smirked to herself, probably aware of the twitching in her host's fingers yet opting to ignore the fact that she was a hair away from being screamed at by an enraged Demon. "I made a list of their personality, appearance, relationships, and Quirks, and they all have correspondence to their previous lives. Descriptive research." She moved on to the third page.
"So you mean you stalked them." Yushiro said from the chair, unimpressed.
"Descriptive research." Gosei emphasized, "how am I supposed to stalk them in broad daylight when I am a Demon? Seriously."
She is choosing not to mention the attire they wore in daytime, Itaji noticed, and very well deflecting the question. The logic is dubious enough to not even fool a ten-year old, and Yushiro knew it.
Pride, perhaps, too dignified to admit that she stalked multiple someones in a suspicious-looking suit. And from Gosei's lack of gloating, it was clear she had been confronted in the process.
Probably by Obanai, if he had another life.
Meanwhile, Gosei continued her spiel.
"Even if their names were completely different due to being scattered all over the world, they seemed to retain their appearances, or, most of it." She waved a blurry photo of a woman with twin pink and lime braids crossing the road, a beret on her head and wearing short skirts and a sweater, the white margin had a hasty Paris, France scribbled on in black marker, "that was my first discovery." The photo was creased at the edges, worn with time. The paper from which it was printed on very likely from what humans now call the 'pre-Quirk" era.
A couple more creases appeared on Yushiro's brow, though he seemed less reluctant to listen. So that was where Gosei was at decades ago, running around Europe and stalking people who looked like potential Demon Slayer reincarnates.
"Here." Gosei produced another that sported a dark circle marked in the left, Itaji moved for the first time from his position and moved to lean in with Yushiro, what he saw made his lips purse and blood race unpleasantly. A third of the picture was black, a wall seemingly blocking the view of a street somewhere. A blonde man with slightly messy locks that reached below his shoulders stood in a window of a building. He wore a bright red hoodie and was smiling, beautiful eyes seemingly burning directly into the camera even though the picture was taken from quite a distance.
The color of his eyes were reduced to a mere smudge from the lowered focus, but Itaji knew what the color is.
Or rather, colors.
"Is that-" he started, voice startled into a quiet breath, as if afraid that volume would attract the owner to them. A deep-rooted fear that had been dormant for millennia began it's push upwards.
"I believe so." The photo was unmarked of location, as if Gosei herself could not stand the prickly sensation of the eyes of who nearly certainly is the Demon that held no emotion under the saccharine shell of a smile. "From what I gather, he is quite a popular bishop in his region. Many ladies enjoy his charm." She removed the picture and tucked it away.
Itaji looked at Yushiro, scanning his face for any indication of wavering. They watched as Gosei took out more pictures still, setting them down on a nearby coffee table and sorting them into two general piles, one being humans and the other Demons. Thankfully, the former seemed larger than the latter.
Somewhere near the end, Yushiro's breath hitched as a picture of a dark-haired woman's mugshot was placed in the Demon pile. The woman's silvery-purple eyes seemed to twinkle serenely out at the onlooker, her dark hair was tied neatly into a bun. Yushiro quickly snatched the photo from the table.
"Is that-"
"Yes." Gosei began gathering up the photos, though she made no move to take that particular one back, "so think about it, Yushiro. They are back, one point or another, there is no denying it now."
"Lady Tamayo…" Yushiro's sharp gaze seemed to soften as he looked at the photo, lips pressed tightly together. His voice trailed off at the end. Even Gosei remained silent. "So he is also back then?" The teal-haired Demon asked abruptly.
"He is." Gosei nodded in affirmation, "and I think he is back for quite a while. I didn't find him back before these Quirks popped up, and trust me, I've been trying. If I did, he would've been dead by now."
"So who is he now?" Itaji asked.
Gosei adverted her gaze, "it was only a guess, and quite a stretch at that, but the hypothesis is full of errors and I can't quite explain it. It wouldn't be beneficial to have you two know it and allow you two to make prejudiced judgement. I need more evidence to support it."
"I could probably find any disproof of your unsupported hypothesis," Yushiro crossed his right leg on top of his left, taking care to gently insert the photo of revived Tamayo into the folds of his haori, "get at it."
"All for One."
"You mean that villain who has been terrorizing Japan? Didn't he get killed by that All Might hero?"
"Yes, but that would mean that he survived for centuries, and Demons do not exist nowadays."
"They do, Gosei-san." Itaji reminded her, "Remember that boy I told you about in the morning?"
"Oh, him? Yes. Though are you sure-"
"What do you mean, 'in the morning'?" Yushiro cut in, his eyes narrowed accusingly at Itaji, "how did you even go out?" His eyes then widened fractionally, "did you…"
"Gosei had bought this set of clothes that block out most sunlight for me-"
"In my defense, it feels horrible, I am still trying to look for the Blue Spider Lily."
Yushiro snorted, "good luck on that, Hashibira's great-grandson got the entire stock killed whilst studying them. Sometime just before the second World War."
Gosei's face went blank, "what."
Itaji did not know about it either, despite the couple of decades that followed, his mountain still did not have postal service, let alone radio coverage. Now that he thought about it, he is still pretty certain that the most 'modern' thing in the mountain was the abandoned electric cable tower that was set there in the twenty-first century. He had to leave soon afterwards, usually a man living in a run-down, cobweb-infested house in the mountains tend to raise some question and legal problems.
"Yes, there was a news article about it," Yushiro crossed his arms, "I thought you would know."
"I was in France at that time!" Gosei clutched at her hair, "are you telling me that I missed my chance and it was so damn close?!"
Yushiro ignored her outburst and turned to Itaji, "you didn't see?"
"Natagumo mountain did not have postal service."
"Hmm." Yushiro lifted up a sleeve of his haori and checked a watch on his wrist, "three hours until sunrise."
That seemed to make Gosei calm down, if only marginally.
"Alright," she pinched the bridge of her nose, "I am pretty sure that a plant cannot go extinct that easily, it is probably only the cultivated samples that are dead, if there is cultivation, then it must have an ancestor somewhere."
"Somewhere," agreed Yushiro, "somewhere that you don't know."
"And since Itaji found a possible Demon that can walk under the sun, there is probably a reason for that, right?"
"-If that boy is a Demon-"
"And Kibutsuji is back, and is still an Overlord that wants to take over the entire world, we are going to kill him, right? For the sake of that doctor you-"
"-shut up."
"No, and therefore it is clear what we should do, right? Eliminate the threat, on our freedom, mind you, find the Blue Spider Lily and gain total immortality, and investigate the source of the Blood Demon Arts, to prevent actual Demons cropping up."
That sounded straightforward enough to Itaji, he glanced at Yushiro, who's lips were pressed so thin they were nearly nonexistent.
"If I said no-"
"I would stay here and annoy you until you say yes."
The Demon sighed, and his blue-eyed companion grinned victoriously.