Tempered by Fire by Planeshunter ( Fate / Stay night )

(Can one truly be overprepared when it comes to venturing into the death world that's the Nasuverse? I think not, and whoever my patron is seemed to agree with me. Wish-fulfillment SI in the Fifth Grail War. Fem!Shirou, Harem builder, Alternate servants... Oh, my!)

000 - It all began with fire.

The world around me was fire.

Patience.

The air was ash, burning through my lungs and clinging to my sweaty face like a mask of embers.

Withstand.

The inferno raged, and all I could hear was the roaring flames.

Endure.

My whole body felt dry, weak and tired, threatening to collapse at every move.

Persist.

My legs cried at the exertion that was taking a single step.

Walk.

But I took it anyway.

Invictus

Your will is absolute, boundless and unbreakable. Factors such as distress, suffering and difficulty mean nothing to you. You're capable of undergoing any disaster without batting an eye, ignoring any amount of pain, remaining mentally untouched by even the most terrible events and even the most fearsome odds will not give you pause. Abilities that would affect your mind or control you are useless. You will never break, never bow and even come a thousand apocalypses you will stand as tall and resolute as ever. Being torn in half, locked into a time loop of endless agony for thousands of years or facing the most hopeless odds are nothing to you.

As I walk through the living hell surrounding me, memories filter in. Knowledge about this place is remembered from a life long past. The Great Fire, the Fourth War, The Grail, Gilgamesh, Excalibur, Kiritsugu Emiya… Shirou.

My pace quickens.

Seeing through the flame and smoke is nothing short of impossible, the constant sting on my too-dry eyes making a feat of willpower to simply keep them open.

I look around, frantically searching.

Must get there before he does. Must find…

There.

A short figure slowly stumbles forward, looking more like a risen dead than a human being. Telling colours apart in this sea of blazing red is impossible, but what I see matches what I was expecting. A hair that could easily be orange, and dull eyes that are maybe amber.

What I wasn't expecting…

Genderbend (x1)

One canon character has his or her gender flipped, this isn't a sudden inexplicable change, but rather something that took effect before is a meta-Domain perk, detection, supernatural or otherwise, is impossible.

… I remember now.

Turning towards her, I walk the short distance between us. This is the first test on my path, a risk I decided to take rather than paying the price to make it a sure thing. As she raises her eyes to look at me, I take the last step, and throw my arms around her.

"I got you." I say. "You're mine, I'll protect you."

Her own arms rise to grip weakly at the back of my shirt, and something that could be a choked sob escapes her lips, before she allows herself to relax in my arms and loses consciousness.

I sit to wait, doing my best to protect her with my own body. It's not long before an adult dressed in black and wearing a frantic expression manages to find us. His face brightens with relief, and he kneels in front of us.

"Her first." My voice comes out raspy and weak, and my throat feels like grinding sandpaper. But I need to play my part, the pain will only sell it better "I promised."

The Twin

You're inserted as the twin of the main character, be it blood related or adopted. We don't judge! This is a meta-Domain perk, detection, supernatural or otherwise, is impossible.

Things change, as they remain the same. The sheath of the strongest sword goes to her, and she still takes weeks to recover for a state of near catatonia. And yet, as opposed to a certain other boy in the same circumstances, she functions enough to follow me anywhere, and use any excuse to grab at me.

… Not that I'm in any condition to move around much. The fire wasn't kind on anyone.

Soon enough though, Emiya Haku regains her life as a functioning human being. If she pays maybe too much attention to her twin's words and seems to seek my validation above all else… Well, Kiritsugu looks relieved she recovered enough for those traits to develop in the first place, and I'm not going to complain.

She's my little sister now.

It's not long before the two of us move in to live with our adopted father in the new Emiya Household, re-inserted into the system through what I can only assume are judicious use of bribes and hypnosis and sent to school to get an education.

Inspired by my encouragement, Haku does her best to make up for her missing time of schooling, striving to excel in every field.

Hounded by my questions and emotional blackmail, Kiritsugu reluctantly teaches us the basics of magecraft. I also talk him into setting aside tools and knowledge of his trade 'in case we ever need them'.

Scared away by my sharp tongue and hurtful words, Fujimura Taiga gives the two of us a wide berth when she's supposedly taking care of us.

… Just kidding, I bribed her with photos of dad.

Snake Tongue

Your words affect people. Be it inspiring them to new heights, dissuade them from taking certain options or making sure they work together even if they normally wouldn't. You can make or unmake people just by talking.

When Kiritsugu passes away, I decide it's time to go full disclosure with my sister. I take her to the porch to watch the sunset, and start talking about things that have been, and things that will come to pass.

I tell her about the Holy Grail War, about Kiritsugu's participation in it, about the taint of the Grail. About the sheat dormant inside her. About our sister growing up in faraway lands, and being taught to hate us. About the future lying in wait. The Fifth War and the most likely participants.

About sweet Sakura, trapped in hell.

About Medusa, so much more than she believes herself to be.

About the Witch of Betrayal, who only wishes for someone she can be loyal to.

About the King of Knights, and her dumb wish.

About the strongest Berserker in the world, and the young girl he'll protect.

About Rin, the Archetype Tsun.

About… Archer, and the distinct possibility he's not summoned this time around.

About the walking corpse filled with worms, and the masked death under his command.

About the naive enforcer destined to die, the ruthless executor, the unlucky child of light, the swallow-cutting legend.

About the King of Heroes, clad in gold. An nigh-unstoppable force that will stand in our way no matter what.

When I finish my explanation, it is the dead of the night. Her eyes find mine without a hint of incredulity or worry.

"What do we do now, nii-san?" I can help but smile at her earnest question. So much like her, to focus on what she can do over matters she cannot control.

"We wait and get ready, Haku." My answer has been ready since before I woke up in that field of fire. "We'll need Servants of our own before we can truly make a difference."

That's just a half-lie, but she's dead on her feet and the truth is complicated. Those words will suffice for now.

At my suggestion, Haku took archery and kendo. Archery will not only be useful once a certain Kouhai joins the archery club but, if her counterpart is something to go by, she'll presumably become proficient enough for her heroic spirit to be eligible for the Archer Class. Kendo because it resonates with her very soul and, now that she knew why, she threw herself into her training with abandon.

Within the realm of magecraft, I had her focusing on her future signature spells, Structural Analysis and Gradient Air. Progress was slower than I hoped, but faster than I feared. Funnily enough, her trigger wasn't the words I would've expected, but something she heard from me exactly once, that she apparently took to heart: "Watch and Learn''.

The double meaning was plain hilarious.

Me, I decided to diversify. Training alongside her once a week, while dedicating the rest of my time to other subjects. From naginata to shinobi tools, modern weaponry, urban guerrilla tactics and many other fields I could somehow reach either through Kiritsugu's old contacts or Taiga's grandfather.

Magecraft doesn't come without trouble, for there's no teacher I can reach and most of their world hates our father's guts, so I have to make do with the tomes and grimoires he left behind. Results are… not a disaster, but I doubt I'll ever get ahead of the basics without a dedicated tutor.

Talented in Every Field

Displaying talent in multiple fields, like martial arts, fine arts, and sexual affairs. You don't lose skill from neglect, and learn faster than normal for matters you only just got started.

Years go by without anything remarkable taking place. In spite of my worries, the Einzbern made no move against us. Even with our slightly more active existence, the Second Owner doesn't take notice either. Same with the undead maggot. And the sadist bastard from the Church.

As high-school years come closer, both of us are nearing the peak of human condition and scratching the surface of Charles Atlas Superpower. Unfortunately that won't be enough to face Servants. Even Kuzuki Souichirou, with his highly unconventional style and absolute mastery, boosted by Caster's enhancements was only able to blindside Saber exactly once.

Still it should be useful against masters. And Shinji.

That's the point we're at when our first day in Homurahara Academy rolls by. We might be able to reach anti-Servant levels with enough time to prepare, but that's something we simply don't have. Less than two years for the start of the War. Clock's ticking.

As we enter the place of learning, we stop to look at each other. The significance of the moment is deep enough to practically taste. Haku has grown well since the fire, way better than her counterpart on the canon timelines did. She's still hard-working and somewhat reserved, but it's easy to get a smile out of her and her sense of humour has that dry and cynical touch I can't help but love.

The best of the boy who never was, together with the best of the Counter-Guardian that hopefully will never be. All of it mixed with a generous portion of just Haku.

She doesn't let herself be taken advantage of either, I made sure he knew to draw the line between being helpful and a doormat.

Me, I'm exactly as successful as I set myself to be. Which is far too successful, now that I'm living it. Having a Secret Appreciation Club in middle school is all sorts of creepy, but girls seem to be drawn to me no matter what.

Pavlovian Reinforcement(Low)

Pleasing you feels good, disappointing or hurting you feels bad. This passive effect is felt by any love interest, more strongly the closer they're to you emotionally. The effect is gradual and subtle enough to be dismissed as natural. This is a meta-Domain perk, detection, supernatural or otherwise, is impossible.

… I'll have to draw a line somewhere, because there's a hard limit on how many women a single man can keep happy and safe. At least until I learn Kage-bunshin.

Huh, maybe I should have a chat with Touko Aozaki at some point in the future. Far future, preferably, I'm pretty sure she hangs with the Mystic Eyes of Fuck Your Very Existence at this point in time and that's someone I'm in no hurry to risk pissing off. Still, food for thought.

On the other side of the coin. I have a… well, a slight problem. Rather, what would be a slight problem in other settings, but could easily see me erased from the face of the planet in Fuyuki.

Mr. Steal Your Girl

Instinctively and strongly disliked by any romantic rivals. They'll be more inclined than usual to follow this 'gut feeling' and will actively work to hinder your interests, to the best of their capabilities. The effect is reduced for romantic rivals who are also love interests, but the effect all perks will be equally diminished for them. This is a meta-Domain perk, detection, supernatural or otherwise, is impossible.

Shinji can go fuck himself with a red-hot kanabo for all I care, but I'm not looking forward to meeting Gilgamesh once the War starts. To think Saber is by far the main heroine I like the least… The irony of the situation is sure to amuse someone up there.

We are more than an hour too early for school. To say we're nervous would be an understatement. Giddy, anxious, impatient and afraid all fall short too. This is what we've been preparing for since the start.

"Ready, nii-san?" She smiles, offering me an extended fist.

"Too late for second thoughts." I can't help but reciprocate her smile, bumping her fist with my own.