This fic is inspired by Sticky Situation by  Professor Quill,   In Bloom by Flight of Fancy,  and to a certain extent Benefits of Saving a Veela by WD_ONeill . Please check them out.

NOTE: This is a SFW version so I can follow ff (dot) net ’s guidelines and for my Magus tiered subs. You can read the uncensored version on Ao3, WN, or HF.

Ch.0 Prologue - Blessings (Curse) of Irisviel von Einzbern (Angra Mainyu)

Disclaimer: Everyone here is at least 18 years of age. We’ll begin the actual story just after they graduate from High School. In Japan, students are usually 18 years old during their last year in High School, by the time they start higher education they’re usually 19 years old. So all scenes of a sexual nature, and references to past sexual experiences were done between adults.

In this story both Sakura and Rin are fraternal twins, and I’m not going through the Illya is a legal loli route.

STORY STARTS

November 1994

As I look upon the cleansing fire I have blessed upon the park of Fuyuki, all those souls freed from the horrid burdens of life as they wail in happiness; as they are touched by my soothing flames; as their fleshy shackles of skin, bones, muscles, and fat immolate.

“!”

Frowning a bit, spying on my husband crying in joy as he saw the result of the miracle I have bestowed upon the town. Frantically searching around making sure everyone is freed from their abuser , life .

“I thought I have thoroughly blessed my husband, he should be here by my side.” I pouted as I frustratingly stomped my foot. “Now if only I could reach my daughter as well.”

“Hmph, either way my blessing was just a little bit weakened. He’ll join me soon.” A yawn suddenly escapes my mouth as I suddenly feel tired. “I’ll probably nap for a bit, I’ll just wake when Kiri is now with me.”

“...?!”

“Oooh baby Kiri, why are you now crying in agony?” I see my love, Kiri, clutching at a child’s outstretched hand. Unlike Kiri, whose face is twisted in agony, this child with red-auburn hair, eyes sparkling in delight as he raises his small tiny hands towards the heavens, reaches out to me, he too, is begging for, is longing for that sweet release from the pains of life.

“No, no, no!” I shouted, despite knowing Kiritsugu Emiya couldn’t hear me as he brought out that sickening perverted sheathe of Saber and placed it within the kid. That must be what prevented Kiri from joining me, and I thought Saber was one of the good ones.

“Dumb Kiri, dumb Saber. I’ll give them a proper lecture when they join me.”

I can see the kid visibly wretch in pain as Avalon took away all of my blessings.

“I always wanted a son, don’t worry my baby, Kiri just didn’t know better; mommy will make everything right.” As I gathered what remains of my energy a condensed ball of Gluttony, Greed, Lust, Sloth, Wrath, Envy, and Pride. “This will turn you into a devil, a being of purity, kindness, and brilliance!”

Just as I voiced out my declaration and bestowed upon my final blessing to mine and Kiri’s new adopted child, everything went dark.

~POV Change~

The sudden engulfment of black flames in the child I had embedded Avalon into, who was on the verge of death, filled me with panic. Burning my hands as I tried removing the child from the blackened flames radiating with pure malice.

To my growing horror, I could see the child not react as he still blankly looked at the sky as his flesh was blackened by the flames engulfing him while Avalon continued to restore damaged flesh. Unfortunately, I know this can’t go on for too long as Saber is no longer present to supply Avalon’s energy.

Visibly seeing the rate of healing slow down, I fumbled around my trench coat for something. This is something my pseudo-mother, Natalia Kaminski *, told me to always bring incase of an emergency.

Quickly removing my jacket, I fumbled around as I patted the inner side of the trench coat’s lining. I sighed in relief as I quickly tore the inner lining to fish out a small vacuum sealed plastic bag; tearing that as well, unfolding a brown parchment.

Natalia was able to provide me with a book's worth of this parchment as I painstakingly stitched this in most of my work clothes as an emergency. Placing the parchment on the warm ground, I tried cycling my O d around  my body converting it into mana. Directing it into the magic circle etched into the parchment.

Glowing light and small bolts of electricity bathed the palms of my hands as it short circuits and begins to dim.

“No, no, no.” Panicking while I checked the state of my circuits.

—Everything but my family crest is damaged or cursed by the flames birthed from the corrupted grail.

Fueled by desperation I imagined a gun firing, my mental trigger to activate my circuits, but this time I’m using it for something different. Grafting my nerves, molding it, as I set my temporary magic circuits upon my soul.

I, muffled my cries of agony as the taste of salt and metal fills my mouth, activating my pseudo-circuits and family crest I channeled mana, one last time, into the magic circle. Slumping forward in exhaustion as I laboriously take in large gulps of air.

Struggling to keep my eyes open as my vision slowly darkens, wallowing in the pit of despair, as I finally accept defeat, giving one last thought of pity towards the burning child just a meter away from me, as I whisper the names of whom I feel the most regret.

“Illya, Iri.”

….

….

….

“thud”

“thud”

“....thud”

Hearing someone approach me, still slumped on my knees, I forced myself to tilt my head to the side. At the edge of my vision I spy a woman with red-hair not much detail as my eyes can’t seem to focus.

“You have summoned me.” She rhetorically declares. “It is I, the Banshee of Hell, Mistress of the Moons, Loyal Guardian, Warrior Princess, Crimson-Haired Whore, the Seer with a camel, the Fifty-Sixth Pillar, the Archduke that governs twenty-six legions; it is I, Runeas Gremory.”

“These days it is a rarity for me to walk amongst this plane, even lately it has actually been a rarity for me to be awake as thousands of years has driven me to boredom as slumber is its only cure.”

“So child what is it you wish for? Let’s cure me of my woes of ennui and let's free you from the burdens that shackle your mortal body.”

Despite knowing what type of being stands before me, hope fills my soul as I unburdened myself from all my troubles.

~POV Change~

12 years later, April 2006

~Thud!~

“Oh– hayou!!” The loud thud of the shoji door is heard as it was violently slid open by our resident ball of energy Taiga Fujimura. Well she really isn’t a resident as she lives just next door but she is considered my guardian here in Japan.

Yawning as I greeted Taiga with a good morning of my own. “Ohayou Sakura, do you need any help with breakfast?”

“You can relax Shirou, I’ll handle this as I only need to wait for the rice to cook and for my dashi to heat up. Though the rice might take 15 to 20 more minutes, I thought last night’s leftover rice was enough so I was only able to prepare the rice last minute.” Sakura says as she stirs the dashi with her right while her left starts being busy doing other things.

“Oooooh, that’ll be a bit troublesome. I don't want to be late for class.” Taiga says while she unties the bow behind her green sundress. “Sakura, could you just pack my share in a bento? At least I have time for this.”

She lets her dress fall to the tatami floor, leaving her in just her long sleeves, and sheer black lace panties. With a crouching start she leaped towards me expertly grabbing at the waistband of my shorts as exposing me to the air while she belly-flops onto the tatami dragging my shorts down.

Despite this being a regular occurrence my sweat drops a bit at the bizarre sight.

Not missing a beat she kneels in front of me, while she orally teases me, a normal sight every other morning.

“Come Shirou, we need to do this fast, it’s still the first week of school and as the responsible adult I need to set an example and not be late.” As I feel the pleasures of her ministrations.

While holding on to me she drags me forward as she lies on her back, pausing a bit as I position myself on top of her. “We could do this later after dinner.” I offered.

“No!” She exclaims as she wraps her legs around my back. “I didn’t get to see you, Rin, and Sakura, for most of the summer. Next year, I’ll be coming with you guys to England.” She loudly declare as she started whining. “With school just starting and you guys attending the University a few stations away, my quick and easy access to you is very limited.”

She further tightens her legs’ hold around my back as our coupling deepens. “I need this! We can no longer do free-access-homerooms!”  More whining occurs as she locks me in place with her legs.

“Wahh Sakura, Shirou’s being mean, just because he started college and he’s all grown up he no longer wants to bother with little old me.” Taiga frustratingly does more of her childish acts as the sound of her pleasure echoes throughout the room.

“Now, now, Taiga-san, Shirou was just trying to help as he doesn’t want you to be late.” Sakura now rummaging in a drawer in the living room as she tries to placate the agitated Taiga.

Grunting as I hooked both her legs around my arms, slamming a kiss at Taiga’s lips as she opened her mouth eager to accept my tongue, I began to resume our intimacy.

“Ohayou.. ahhhhh.. Sakura.. arghhhh.. Shirou, Taiga.” A  groggy Rin, in an oversized shirt, enters the dining room, yawning as she pandiculates and stretches, lifting up her shirt, exposing her nether regions to the cold morning air.

Rin sits down at the head of the chabudai* giving her a clear view of me and Taiga’s fevered exercise. Sakura, approaching Rin, places down a cup of steaming black coffee.

“Thanks, Sakura,” Rin said, as she raised her knee tucking her other feet under and started to get in the mood while sipping her hot-steamy beverage watching me with my regular early morning exertion.

The picturesque sight of this morning’s activities excites me even more as the pleasure rises, eventually ending our coital ritual.

“Gochisousama-deshita!” I raised a single eyebrow at Taiga as she just laughed in return.

Sakura, whom I can hear a distinct sound of buzzing underneath her skirt, hands both of us towels and some body freshener. She also places a clothed wrapped bento beside Taiga.

Taiga, peeking at the wall clock, begins to frantically fix herself as she rushes towards the exit not forgetting to give both Sakura and I a thank you for the meal.

Shuffling towards the chabudai* I grabbed my chopsticks just as Sakura placed the last bowl of rice.

Suddenly we hear thundering steps, as the shogi door slams open the second time this morning. “Shirou! I forgot to tell you that my niece Ritsuka just arrived this morning. She too, is enrolled at the university you guys are attending. I instructed her to wait for you at the Fuyuki station. Here!”

Taiga then chucks, what I thought at first was a piece of paper, but just as it slides on the tatami and stops a meter before me, I can see that it was a picture of a red-headed girl smiling showing a peace sign.

“That’s what she looks like, I told her that you’ll show her around campus and Fuyuki after classes, see ya again!” She slams the shogi door close as you can hear her thundering steps  get weaker as she exits the estate.

A collective sigh escapes everyone’s mouth at the antics of our supposed responsible guardian.

“Hey, Shirou it’s Sakura’s ride tonight right? Me and Sakura’s morning classes were cancelled so why don’t you throw me a bone just before you leave?” Rin winks at me as she lifts her shirt and exposes herself to me.

Sakura sighed. “Rin, don’t use that crude word to describe our night time activities.” Sakura said as she lectures Rin.

“Well with how you do it with Shirou, I’d say crude would be a valid description.” Rin rebutted.

Harrumphing at Rin she turns to me as she discreetly pushes into my 2nd knuckle of my left pinky, as my hand is currently resting on the corner of the chabudai*. feeling a constant vibration from her contact.

“I can feed you while you can give Rin what she wants.” Sakura offered much to Rin’s delight.

Exiting the Emiya Estate with a bike, as I started to pedal my way towards Fuyuki Station. I let my mind wander as the station is on the other side of the river, it’ll take probably 20-30 minutes for me to reach it.

Thinking about how my life has changed these past two years. I was found by my savior, Kiritsugu Emiya, near the center of the Fuyuki Fire, close to the brink of death. Unfortunately, even with the strong magical healing artifact he has embedded within my body the cursed flames began to lash back; and was in a fight with the artifact for dominance over my body.

In the end I was left with this, according to my guardian from the moonlit world, cursed-blessing. The strong artifact of fae origin continuously remade my body as the curse too destroyed and remade my body.

With the help of my current guardian from the moonlit world, they were able to dispel the cursed flames but still one of the curses latched on to my soul, the sin of lust.

The combination between the curse and the artifact of fae origin has changed my nature significantly. As my body was continuously being destroyed and reconstructed almost every piece of my body was eventually replaced. In the end I was transformed into what I am right now, still with a bit of humanity left.

The main side effect of this transformation was the blessing-curse on my body, it is basically a passive charm my body exudes akin to what incubus, succubus, veelas, sirens, and some dead apostles exude; but unlike those charms mine is more selective and gradual.

People who hold affection, attraction, and lust towards me and are reciprocated by me no matter what level begins to get pulled. This pull starts small they don’t just go straight to fucking and they still retain their will and freedom of mind.

It just slowly removes their inhibitions and highlights their wants. Luckily my guardian had the presence of mind to provide me with an artifact that inhibited this aura while I was a kid. The artifact was unfortunately overloaded by the time I reached my majority at 18 years old, last year.

Shaking my reminiscing away, while slowing down my bike as I reached the entrance of Fuyuki Station.

While folding my bike into a more compact form, somebody put their arms around my shoulder greeting me.

“Hey Shirou! Let’s go to Kuoh together!” What greeted me was a girl with short-brown hair, wearing a maroon sweater and short skirt. She, too, has her bike already folded beside her.

“Oh, good morning Ayako don’t you feel cold?” I asked, looking down at her skirt. I never could understand girls who wear short skirts in the cold as spring just started, you could still feel some of the biting cold in the air.

She just gave me a knowing grin. “Well obviously it's for easy access, how else would we spend our train ride to Kuoh?” She says this as she already has her hand on me.

Mitsuzuri, Ayako, she’s someone I knew since middle school as we were both part of the archery club. She is also Rin’s official girlfriend ever since highschool, so she regularly stays over at our place.

“I do need to escort someone around today. Do you want to join us?” I asked as we started climbing up the steps of the station.

“Oh, is that Taiga-sensei’s niece? I heard her talk about it two days ago.”

Grumbling a bit at the fact that I am the last one to learn about this information.

Ayako laughed while still gently rubbing her hand over my pants. “I’m guessing, typical of Taiga-sensei, she told you about it last minute?”

“Yes, it’s fine, at least it’s better than forgetting it. I would hate to be her niece just waiting for nothing in a place I’m unfamiliar with.”

“Well, I think even if Taiga-sensei forgets to inform you it would have worked out either way.”

Turning to Ayako I asked, “What makes you say that?”

My head turns towards the direction Ayako is pointing at right now. I can clearly see the girl from the picture waving a placard with my name on it. Feeling bewildered at the sight, we approached the red-headed girl.

“Hey, name’s Shirou Emiya, Taiga sent me to escort you around campus and later on around Fuyuki. Nice to meet you.”

“Oh hey, thanks for having me, I’m Ritsuka Fujimura.” The red-head now sporting a tinge of red on her face as Ayako squats down and starts to administer fellatio.

Pausing from her ministrations. “Hey, name’s Ayako Mitsuzuri, I’m this guy’s girlfriend-in-law.”

“Is that correct?” Ayako asks as she tilts her head upwards at me in askance. “I’m your girlfriend’s girlfriend, hence girlfriend-in-law.”

Before Ritsuka or I could reply, our train had just arrived. While still carrying my folded bike Ayako begins to lead me into one of the train’s coaches while still holding on to me, while Ritsuka follows us.

Luckily we spy several empty seats as Ayako directs me to sit on one of them. She then turns toward Ritsuka and pats the empty seat beside me.

“Hey, can you hold on to me?” The train begins to move as Ayako begins to mount me with both feet on my side.

“So tell us about yourself.” Ayako asks as the noise of our coupling is exposed to the train’s coach.

Oh yeah, one of the other side effects of this charm of mine is that common sense is a little skewed when anyone sees me and any of my partners doing it. Most men, and women, who aren’t attracted to me completely ignore it as our rutting doesn’t even register in their minds.

We even tested it as even through the lens of a CCTV camera people just continue on as they are as if nothing weird is happening.

While those who are attracted to me, men or women, begin to watch or just masturbate. They too are not registered by the unaffected party. Only people who are close emotionally, those whom I have reciprocal feelings for, and have started some form of bond or relationship with actively do this.

Though, I sometimes get asked and approached by pretty ladies who usually have lower inhibitions, to join.

After that admittedly fun ride and getting to know Ritsuka for a bit, though not by much as Ayako provoked me too much. She currently is resting on my back passed out with a goofy pleased smile on her lips.

Around me is Ritsuka Fujimura, our new redhead friend holding on to my bag and her bike. To my left are professors from Kuoh University whom we met on the train due to me offering my seat to their injured friend with a cast on her right foot. She is currently on the phone talking to someone who was supposed to pick them up.

While the one in the middle, who thankfully offered to carry our folded bikes, is now watching their third member squat down in front of me offering to clean me up.

“Professor Cha, Professor Kim, and Professor Han— Oh and Shirou?”

And that’s how Runeas and Vivian, both my guardians in the moonlit world, found us this morning.

Me with a passed out friend on my back, a new friend beside me blushing at the sight of our newly met professor “cleaning” me up while her co-professors watched..

With a large grin Runeas just invited us to continue in the van.

-=&<o>&=-

END

*Did you know that Natalia Kaminski, Kiritsugu Emiya’s master/adoptive mother; the one who got sacrificed when Kiritsugu shot an RPG at a Dead Apostle infested commercial flight, by lore is actually half-demon. I just repurposed her to be half–devil in this story.

*Note: Chabudai -  is a short-legged, low-to-the-ground table used in traditional Japanese homes. It's designed for use while sitting on the floor, typically with tatami mats or floor cushions (zabuton). Chabudai are used for various purposes, including eating, studying, or working.