Creation began on 03-22-24

Creation ended on 03-25-24

Neon Genesis Evangelion

Demon Slayer Evangelion

A/N: This will be unlike what I've done before when creating crossover stories due to situations within situations that lead to different outcomes than what we may have seen previously.

Shinji Ikari awoke to the feeling of being cold and exposed. As his vision corrected itself upon opening his eyes, he found himself in a white wilderness. A snow-covered wilderness; he had never seen snow before, and as he felt the cold of it for the first time, he had a question that was rational.

Where…am I? He wonders as he rises up to a sitting position, seeing that his plugsuit was gone, replaced by strange clothing that was reminiscent of an earlier time period associated with Japan. What is this place?

"So, you're finally awake, stranger," he hears a voice that sounded like his, only less…like he had nothing going on in his life. "Can you stand?"

He turned to his left and saw…someone that seemed to resemble himself, only…he looked like he was dressed for a throw down with a lot of people. The young man was wearing a dark hakama…but adorning it like a bizarre form of decoration that didn't belong to the period the outfit was a part of, he wore a bandolier full of shotgun shells and a scabbard for a shotgun on his back. If Shinji had to wager, this man probably had other guns somewhere on his person, hidden by his hakama.

"Who…who are you?" He asks him.

"Tell me who are first," the man utters back.

"Ikari, Shinji."

"Shinji Ikari? As in the son of Yui and Gendo Ikari?"

"Yes."

"That shouldn't be possible; nobody with that name or those parents exists in this timeline yet. This is the Taishō Period. Not even the beginnings of the first global war."

The Taishō Period? I'm in the early years of the nineteen-hundreds?

"And in answer to your question of who I am, my name is Death, the Endgame. In a past life, I was once a young man by the name of Shinji Ikari, same as you."

"You're me?"

"I used to be someone like you…in a different life. What were you doing…before you ended up here in a world you shouldn't be in?"

"I was…inside the Eva…and I was facing an Angel…and I got sucked into a shadow."

"Dimensional displacement."

"What?"

"Was it the Twelfth Angel? Black and white, zebra-esqued, sphere-shaped?"

"Yes?"

"You're not the first person to encounter such a phenomenon, and I doubt you'll be the last, either. It's a scenario that seems to splinter across the whole of infinity that we currently occupy. You're just another member of an endless well of universes where the Evangelion is a constant in the universe that all things integrate. I find it unusual that you wind up here, though, as the Eva won't exist for over a century from now. And what's with that sword?"

"Sword?"

Death points to his left side, and Shinji notices a sword that he hadn't seen before. It was sheathed in a purple and green scabbard, its tsuba shaped like a ring comprised of heads shaped like Unit-01, four in total, all facing outward, and the hilt resembling a Prog. Knife's handle. The way it looked made Shinji suspect that it was like the Eva, or modeled after the Eva. He picked it up and unsheathed it, revealing a long blade with strange runes etched into.

"Aaaurgh!" Death gasps, raising up a small, curved blade of his own, a kama sickle, revealing his right hand was nothing but bone. "That blade…is not of this world."

Shinji looks at his face, seeing that it was paler than his own, his eyes lifeless, but exhibiting a degree of emotion that was clearly evident of being bothered by the sight of the sword.

"Cover it up," Death tells him. "Cover it up! It offends me!"

He quickly re-sheathed the blade and put it down, and Death lowered his blade.

"I'm sorry," he tells him.

"That sword…is the Eva you were piloting," Death reveals to him. "The runes engraved on it…are an incantation meant to unleash an unforgiving force the Eva represents."

-x-

Death took Shinji to a nearby cave and built a fire. It was late in the day, and unlike himself, Shinji was alive and needed to regain his health gradually after waking up in a cold environment. The mortal boy was fortunate that the deceased youth had been on a gathering and had fish and produce with him prior to finding him in the snow.

"So…Death?" Shinji asks him. "As in…the Grim Reaper? Angel of Death?"

"Yes," Death answers him, "and no. I'm also a member of the Horsemen of the Restorative, a faction of guardians under the heavens tasked with restoring the order of the Earth."

"How did you get to be one of them?"

"A deity visited my brother and I shortly after I took my last breath…and offered me a proposition with the promise of redemption for my soul. I accepted…and carried out my duty as the Pale Rider of the Restorative to the utmost peak of performance. The world I once resided in was restored to its previous state, cleansed of its excessive sins, the people that lost their lives revived to relive them. It was a grand sight to behold, a true miracle for the world. An act of the kami…and the people that believed in their righteousness."

"So…you were handpicked by a deity…to save the world."

"More or less, yes."

"And…you saved the world. But…you're still the Grim Reaper?"

"That…is because I chose to continue being the Horseman of Death. My reward for a new life on hold until I am ready to take it, however long that may be. Time is a construct that doesn't exist for me as a damned soul redeemed. In the end…I went from a man condemned to Hell by the actions of his past…to being a man freed from Hell. In the end…I don't really see myself living among the mortals any time soon or in the future, but I don't regret that choice. My only regrets were the life I once had not really being a life and with relatives that would rather chastise me for the mere fact of existing and condemning me to a fate that nobody, good or bad, should ever condemn their children to. But what about you? What kind of life did you have in your past?"

"Me? I…"

"We might've lived in different times, but we have our similarities, don't we? Whatever life you had, it doesn't change the fact that we're both fractured pieces of the same person reflected in the mirror, the ripples in the water made by the same stone tossed into the river that flows downstream. Each ripple in the water, each crack in the mirror, all associated with the same individual across the whole of existence."

And so, Shinji told Death about himself, down to the day he met his father and how he was forced to pilot the Evangelion against the Angels…up to the day he fought against the Twelfth Angel and ended up here. It wasn't really any different from any other version of himself that probably had the same background, but Death assured him that each alternate of him had a similar past that led up to that day…but ended up going down a different future because of where they ended up upon facing the Twelfth Angel, which was connected to other possibilities in existence, including the impossibilities that mankind could only begin to imagine with disbelief. The ideas of alternate realities, temporal phenomena, even just the mere thought of stumbling across the echoes of worlds beyond the ones they had left and had to find a way to survive in. The only minor difference between these two was that, unlike Death, who once lived with an aunt and uncle and cousin, this Shinji had no other relatives to speak of, as he lived with an instructor associated with his dead mother.

"Have you met others, then?" Shinji asks him. "Other versions of ourselves?"

"Many, many times over," Death answers. "In many ways, they all found an escape from the Eva and their parents because of the differences in their futures. One found his salvation through unwanted immortality he received from the attempt on his life by his aunt at the age of ten, after an attempt to poison him over time only stunted his physical growth and development. Another who was like you, who faced the Twelfth Angel, ended up in a world where science and mysticism are commonplace and the Eva he piloted evolved into a benevolent force after consuming a dragon of unforgivable malice. He ended up relocating to that world and had a family with a girl that actually loves him. Another alternate ended up in a different world the Evas and Angels never existed…and he was a descendant of a deity that chose a life of mortality and relationships ruled by love over constant procreation and evolutionary goals. It turned out a version of us actually lived in that world, but ended up having to take his own life to protect the life of someone he loves. He was in Limbo for a time until the alternate showed up and they both met with circumstances that led to them fusing their souls together in one…and they actually have a better life where they are. I can't fault them for their decision, as it enabled one to return to life and the other to undo the ravages of their former world with god-like power tied to their heritage once they passed the test that had been presented to them in order to obtain the power that was promised only a member of the bloodline. But I wonder…what does fate have in store for you? Why are you here? What is there for you to do…and, if possible, what must you do to return to your world?"

Shinji didn't know the answers to those questions, either.

"Maybe his fate here has to do with that sword, brother," they both heard someone's voice in the cave, and Shinji saw, floating beside Death on his right, a baby wrapped in a red blanket with their right arm exposed.

"Aaah!" He gasps.

"This is Mako," Death introduces the baby to him. "He's my elder twin. He's also the first and only Horseman of Unity for the Restorative. So far."

"Mako? Twin brother? But…he's a…"

"Yes, we know," the baby, Mako, expressed, floating over to him. "In the multiverse, I'm among the rarities associated with my brother. Never underestimate the power of twins."

"So…how did you…you know?"

"Heh. An accident. Our father dropped me the first time he held me. I don't really hold grudges for that being the end of my life. If any asks, I simply state that I received the lesser fate that befalls twins born to reckless parents that think they're worthy to change the land the kami gifted us with."

Shinji looks over at Death, whose face seemed rather devoid of emotion, almost like Rei's, but it was in the eyes. Those lifeless eyes that held something he couldn't fathom, like a storm of retribution. If his brother did receive the lesser fate of what befell them, what fate befell Death when he was alive? And how was it the worse of the two fates?

"Uh…you think my being here has something…to do with that sword?" He asks Mako, pointing to the sword that offended his brother.

"We're all associated with universes where the Eva is a constant in each one, something our parents exploit to their own benefit above all else. We either find a way to escape it or we bend it our own will in order to break from the cruel fate they have tried to deal us with, time and again in the lives we either have or had."

The twins informed Shinji of some of the worst things one could do with the Evangelion, which included the destroying of the world one knew just to remake it into one that was to one's liking over simply using it to do a noble act of kindness. To learn that in nearly every universe in which the Eva existed…made him worry about what was going on in his world…and why his parents chose this route over something else that was…preferable to something this cruel, this heartless, this unforgivable. Some versions of himself had been able to get away from them by relocating to a different world free from the Eva, others found a way to take control of the Eva away from their parents and bend them to their will to undo the ravages of Second Impact. But what was to be his fate? Would he find a way to take control away from them…or would he be forced to consider relocating to another world where the Eva was nonexistent?

"Are those the only choices?" He asks the twins.

"Those are the only ones that have actually worked," Death explains to him. "In some worlds, our salvation is sometimes in the hands of people we barely know…but over time become the people we end up finding hope for a better future in. Different friends…different relatives, even relatives of which there are no blood ties to…and they end up being better than the people we're actually related to in more ways than one can imagine. There was a case in one world where a version of us committed a taboo, just to bring back his mother because he lived with relatives that despised him…and he ended up with someone that was different from what he longed for…but was who he needed to save him from a grim future. This woman that was modeled after his mother was a case of spiritual disillusionment, or rather…spiritual fracturing between right and wrong; if you met a woman by the name of Ritsuko Akagi, then you must know of the MAGI. It was built by her mother, Naoko Akagi, based only on three aspects of herself that actually helps to define other women of her status: Women, scientists, mothers. Each aspect exists within the person, but which one is the dominant aspect? In the case of the Yui Ikari that was brought to life as a replacement incarnation for the mother that Shinji was longing for, she was merely half a woman that carried the motherly aspect of the actual woman, causing the leftover spirit within the Eva to retain the scientist aspect, and therefore resulting in a woman that couldn't connect with her son on any level, even if someone else wanted her to. A woman that only knows how to be a scientist can never measure up to a woman that chooses to be a mother for the right reasons that led her to caring for someone that depends on her. In the end, that Yui Ikari was among the people that are listed as being the benevolent of souls that are involved in a struggle to save the multiverse. We're all still being gathered, every single one of us observed, evaluated, trying to decide if we're able to do something to help others trapped in a darkness that needs to be lifted…or if there are others that can do better than ourselves."

"I feel like I'm in a nightmare right now," Shinji tells them.

"We all often feel like that," Death responds. "It's the darkest part of who we each are. We're either victims, slaves, broken remnants, survivors, defiers of unjust fates…or regular people that only want the simplicity of an actual life without strings attached to it. What do you want, Shinji Ikari? What do you really want?"

"What I want is… What am I allowed to want?"

"What is anyone that discovers an awful truth about the monsters their parents are allowed to want for themselves?" Mako states. "Anyone that discovers such a truth can desire whatever it is that their hearts want: Happiness, love, an actual life over the half-assed one they were given, etc. Do you know the difference between people who are parents that choose divinity over their own children? They might get to live forever…but they outlast their children that may suffer because of their self-interests that they put before them. Who does that? Who would choose that? If divinity and power is all they want in life, why choose the path of parenthood? Why bring children into the world…if you are not fully committed to caring for them? When you choose to become a parent with the one you share your life with, you willingly forfeit your freedom to do as you please in favor of making sure your children know right from wrong, to do better than you have with your life."

"Not everyone practices that."

"And they're the ones that will fail to make sure their children do not suffer from the cruelties that they are a part of," Death declares, "but in this world, in this time, there are other cruelties at work that rival the arrogance of mortals."

"Like what?"

"Demons. In this world, there are demons that dwell in the shadows of the night, preying upon the innocent, on regular people, to feast upon them to grow stronger and tap into greater abilities that border on the supernatural. Unfortunately, the public is hardly aware that demons exist, ignorant to their presence and the evil that they spread. Some people seek out demons to do one of two things: Eliminate them…or join their cabal in exchange for many benefits that they possess as demons."

"Demons? Like…horns and claws? Wings and tails? Red eyes and fangs? Those kinds of demons actually exist here?"

"Everything except for the wings; demons can't fly, but they jump real high and control their descent if they have a strong measure of power to enable them. Maybe that sword is meant to protect you against them if you come across them in the future."

Shinji looks at the sword, but doubts that it would protect him against anyone; he'd been a pilot of the Eva just enough to accept that he had no skills as a fighter, and he never once picked up a sword to do anything with it.

"I know that look on your face," Death tells him, "and it's an indication of your doubt in your abilities. So, question: Have you ever committed any form of violence that was in defense of your life or someone else's that didn't require the use of the Eva?"

"No," he answers. "Never."

"Before I died, when I was like you, alive and without any actual concern towards my well-being by others, I was given a hard time by relatives that despised me. One day, they all went too far in making my life Hell on Earth, so I made them take the one-way express to Hell for the suffering they gave me, and in the process, I found myself capable of doing things that, while not what I initially expected of myself, were quite a revelation because of how exhilarating each act became in the silence I committed myself to."

"You…murdered your relatives?"

"They brought it upon themselves to start with. At any point in our lives, one way or another, we get the urge to want to torment the people that give us pain instead of acceptance, hate instead of love, grief instead of happiness. Sooner or later, whether we choose to fight against these drives or not, we give in and express our darker thoughts and feelings about how we feel for those that push us over the edge. I only murdered those that were being cruel to me on purpose before I was incarcerated in a mental institution and left there to waste away until I was fourteen, the same time that bastard had me transferred to Tokyo-3 in order to pilot the Eva, but I had other plans. I escaped from him with the aim to return and kill him, the last of the family members that had given me pain and despair. In the ten days between my escape and my preparations for revenge, I became more than what I thought I was capable of. Some claim that your childhood ends the moment you know you're going to die, but that's not true for any of us. For us, childhood ends the moment our mother decides to hit the metaphorical road trade away her flesh and blood for false divinity for a black-hearted belief she couldn't achieve as a person bound by mortality…and further aggravated by our father doing no better when he decides we are of no use to him as we are when we're little. I haven't been a child since my dreams became nightmares and my parents became the monsters I had to silence for their sins that I refused to pay for. The sins of the parents should fall upon the parents, not the children. And if they can't atone for them, then they should be dealt with for their sins. In the end, I lived more in those ten days than I had ever lived in my fourteen years of life that pale in comparison to my existence as the Horseman of Death. In those days…I truly lived."

Shinji felt it was impossible to do that, to live more in the time one had left to live than to do so in one's entire life, but here he was, listening to the life story of someone that had been himself in another life, and one where he had other relatives beside his parents…and they were just as cold to him as his father had been, resulting in lives being cut down to mere days because of the need for vengeance. A young man that had lived more within the time he had left, making an impact on people that was, while not the kind of impact he would've left, the kind that only someone with so little time could actually afford to leave behind. Running, fighting, hiding, killing, these were what defined the life that this former Shinji Ikari had before he died, and in a way were carried on in his horseman guise.

"Even so, I have never been able to fight for anyone or anything, including myself, outside the Eva," he tells the twins. "I'm not a fighter."

"Hey," went Mako, "neither were we…until we had to show that we could fight. Some people can be fighters if they choose to stand up for something or someone they believe in. And when the fighting is done, they can walk away and be something else that they prefer over conflict. Is there anything you wanted to be…before you ended up in the Eva? Any ambitions or interests that you would've chosen had you had time and space available to choose for yourself?"

"If I had a choice? Probably be a chef."

"Why?" Death asks.

"Cooking has…been a small comfort for me, really."

"An escape from the chaos of the world? Something you can control because it can't cause you pain? And you take joy in having your dishes tasted by people that probably have no skill for it and can't cook, even to save themselves from starvation?"

"Something like that."

"Impressive. An impressive goal. A positive ambition. If you can't fight for anything else, fight for that ambition. Fight for that goal. Defend it with all that you are."

-x-

There was nothing to salvage. Literally, nothing to salvage. The Twelfth Angel had been completely destroyed, Eva and all. The buildings that had been absorbed were restored, but there was no trace of Unit-01 or the pilot. This left NERV in a bind, even though it was the heads of NERV that allowed for this operation to take place.

The plan to use all remaining N² explosives with Eva Units-00 and 02 expanding their AT-Fields to disrupt the Angel's AT-Field and the Dirac Sea that made up its body caused it to come undone, but in the process, Unit-01 and its pilot were not recovered at all. The chances of survival were less than slim, practically nonexistent. There wasn't even a factor of a percentage in which Ritsuko Akagi expected the Eva to have been transported to another reality prior to the operation. But in the end, Gendo Ikari allowed for the operation to be carried out…and Dr. Akagi was simply the one that carried it out, all for the sake of salvaging the Eva, even at the cost of destroying it; it could be rebuilt as long as there was a trace of its core to be salvaged.

Even with the operation considered a success because the Angel was defeated, it felt like a loss because a life was sacrificed.

-x-

Although it was clear that the sword offended his deceased counterpart immensely, mostly because it was the Eva their mother devoted herself to in every sense of the word, Shinji did appreciate Death's willingness to tolerate his use of the weapon to demonstrate at least some rudimentary skill. But Shinji found it most unusual that such a weapon be capable of destroying the world would end up in his possession when he suspected that Death, or anyone else for that matter, could just take it from him without any trouble and sell it for a high price if it possessed any value as an antique. Even with his Eva-related training, Shinji was practically less than an amateur when it came to wielding a blade, but Mako, the more positive twin, suspected that Shinji was, due to his passiveness and the fragility of his own ego, was refraining from trying to harm Death with the sword.

Clash! Death, even when he held back, was still a force to be reckoned with when it came to the kama, as Shinji was forced to one knee each time he tried to block the blade.

"Time out!" Mako yells, and Death backs away. "We have a serious problem with Shinji here."

"Even when I hold back, I'm not holding back," Death explains to his brother.

"No, Death, you holding back isn't the problem. The problem is Shinji himself. He's the one holding back."

"What?" Shinji questions.

"You're just using the sword to block, but you're not putting in any effort to counter Death. Each time you defended, he brought you down to one knee, and each time he did so, he had ample opportunity to fatally show you that each time you were put down, he could've ended your life. It's as though you're refraining from being offensive because, either consciously or subconsciously, you don't want to engage with anyone, even to save your own life. In the eventuality where you're on your own out here in this world, you will not survive if you can't defend yourself against someone or something that comes after you. We're not asking you to become violent constantly. We're asking you to be able to defend yourself and others that can't defend themselves against a potential threat should it ever come to that. Certain demons will not show an ounce of mercy or weakness to anyone they come across, even though most demons were once human that chose to become demons in exchange for things they couldn't have as humans, like immortality or power. Some become demons for the sake of surviving, others for revenge against old rivals over trivial reasons. Either way, whatever motivated them to begin with, their negativity will include an unwillingness to show mercy or restraint against whoever they come across. For most, people are no different from food or playthings. In the end, should you encounter one that behaves like that, will you hesitate to defend yourself or someone else…or will you stand and fight to protect what matters?"

Then, Shinji saw the ghost baby change in front of them, assuming a form that resembled Death's, but the clothing style was different, dressed in a hakama with lighter shades blue and white, holding a halberd. Because Death was the only one of them that actually lived to age into his teens before he died, it was the likelihood that Mako, the twin that died as a baby, took on the physical appearance of his brother's teenage state, but where they differed, besides the aesthetics in their attire, was how Mako had this light in his eyes that Death didn't possess. It was as though the elder twin, due to his premature death from being dropped, still had this sense of compassion, of seeing the good in people that was less aggressive than his brother's ability to see and feel disgust towards the evil and ugliness in people that he went after.

"Whoa," Shinji expresses.

"Impressive, no?" Mako says as he raises his halberd up. "I was the Horseman of Unity for the Restorative. The fifth horseman. An auxiliary, if you will, but I was equally strong as my brother here. So, tell me, Shinji Ikari: Do you think you have what it takes to become a Demon Slayer? Do you have what it takes to hunt down the most evil and dangerous of demons to ensure the safety of the people and pursue your goal later in life? Do you? Shall we find out?"

Shinji held up his sword again, this time against another version of himself that was the elder twin of a version of himself that was dealt the most unforgivable of rotten childhoods by their families. He wasn't sure if this Mako, the Unity was any different from Death, the Endgame when it came to combat, but he was in no position to complain. These twins were teaching him how to fight against an enemy that was far from human and wouldn't go down easily. If he could survive being educated by these two from a different universe where they died before becoming heroes in their own right and were tasked by the heavens to restore the Earth and its innocent lives to a pre-Second Impact state, then he had a shot of joining the unofficial organization that was the Demon Slayer Corps. Not a great shot…but a shot.

All he had to do was adjust to his current predicament.

To be continued…

A/N: Alright, here's the first chapter of the new crossover. The idea is that the Shinji that stumbled into the world of Demon Slayer receives help from his A Maddening/New Cause counterpart that has been around far longer because he chose not to accept his reward just yet, and even after joining the Demon Slayers, the two and Mako will likely stick together until Shinji decides to work separate from the twins. And as for the sword that used to be Unit-01, it will be part of Shinji's arsenal. What do you expect to see in the future?