"Not a blade of Justice, but a Protector of Humanity"

Honkai Impact 3rd x Fate/stay night crossover novel

Prologue: The rebirth of a dream, a final miracle

On the porch of the Emiya Residence, as a man and his son sit and look up at the stars, the father looks up at the full moon with a small smile of relief on his face.

"When I was a boy, I wanted to be a champion of justice."

"A Champion of Justice?"

"Yeah… I did, Shirou. Hard to believe, huh?"

"What happened then, old man? Did you… give up?"

"Perhaps I did, a long, long time ago… All my life, I pursued that ideal, never questioning it. But now, I wonder… did I go wrong somewhere…?"

"You're speaking more weirdly than normal, Kiritsugu. Maybe the tea you drank today was off."

"Haha, it's not that, Shirou… perhaps this night is making my mind wander more than usual. In trying to become a hero, I went through many things, both tragic and fortunate. In the beginning, I lost my mother, then my childhood friend, along with the island I was raised on. My father… he also died, because of his pride and arrogance to think he could escape consequences… justice for being the cause of the island's loss himself. But in return, I was rescued by someone. After saving me, you could say Natalia became a mother figure to me. She taught me a way to become a champion of justice, raising me to adulthood… only for me to have to sacrifice her to save a city from a massive outbreak. From then on, I walked the path of saving [the many at cost of the one.] Later, I was even blessed with a wife and daughter… only for me to lose them as well… to the Fuyuki Fire."

"And yet, through that fire… I saved you. In the hell where I lost everything, even my long ideal, I was able to save one person, and be able to adopt him as my son just like how Natalia saved me. Because I pursued justice, I reaped a high price… yet I gained the greatest reward… by being able to call you my son."

"…I never knew you felt that way… I'm happy to call you my dad too, Kiritsugu."

"That's a relief to hear… I'm not sure if I regret trying to become a Hero of Justice, but I'm grateful to be able to meet you, Shirou."

"Then… I'll take your place! I'll become a hero that can save everyone, just like how you saved me!"

The father chuckled, about to dismiss this statement as another joke… yet when he glanced over at the son, he saw the seriousness in Shirou's face. A glimmer of fear appeared in his heart.

"No. Shirou. It's good to want to save others, but this world makes that impossible. I sought a miracle to change that, yet failed to protect those around me in the process. As one who walked this path before you, my advice is to become a protector instead. Protect others from the evils of the world, find something that you think must truly be protected and use all your might to defend it, so you will never lose those close to you like I have."

The son was stunned at his father's words, leaving the two in silence for a while as he mulled over his thoughts. Then Shirou thought of something.

"Then, how about... a Protector of Humanity?"

"…Huh?"

"Instead of being a Hero of Justice, I'll become a Protector of Humanity. Instead of delivering justice, I'll provide salvation to others instead! I'll protect humanity from all the evils of the world, never giving up, even if I stumble and fall along the way, because I can just pick myself back up!"

Kiritsugu took in his son's words, finding them completely unexpected. He had not thought his son would take his warnings to heart and change his desire in such a way. Pride and satisfaction replaced fear, and the relieved father let out a long laugh.

"Ha...Haha…HAHAHAHA! Yes, that is a good ideal to pursue, much better than mine when I was your age! Indeed, you're right, it is better to provide salvation instead of justice, just like how it's not wrong to help others in front of you. But remember to keep in mind that you can't protect everyone all at once, so protect those close to you instead, alright?"

"Yeah, leave it to me, Otou-san(dad). I'll protect the world in your place, it's a promise!"

"Haha, I feel a huge weight has been lifted off my shoulders. I'm relieved, knowing I can leave everything to you…"

"Thank you, Shirou."

With one last smile, the father said his last words to his son, and an unsung hero passed on peacefully. The boy watched his father finally rest, his final moments lacking any regrets. Kiritsugu never told Shirou of his mercenary acts, the blood of others he had spilled, nor of his actual role in the Fuyuki Fire, or the darkness hidden in a great cave in the nearby Mt Enzo, yet his son had taken his father's dream and turned it into something better.

"Don't worry, old man, I'll become a Protector of Humanity for you."

Almost a decade later, as Emiya Shirou finally outlasted his nemesis Kotomine Kirei and has already projected the sword Excalibur to destroy All the World's Evils once and for all, his mind, body and soul had already begun breaking apart due to the extreme strain of projecting the last phantasm of the world, even when already on the brink of death from overuse of his alternate older self's arm. Now only almost incapable of recognizing anything around him except the objective in front of him, he is about to swing the holy sword in his hands, mind only executing its last task like an automaton before its shutdown, when he hears a voice, coming from behind him.

"Oh, I was almost too late… you have already projected Excalibur and your soul is already fragmenting…", the sword automaton pauses. Somehow, he/it? recognizes this person, but their mind is too far gone, it cannot remember anything. The while clad lady with red eyes and white hair walks towards it and the corrupted Greater Grail, continuing to speak, "Sorry about this small body of your big sister, Shirou, I couldn't get here fast enough to save your body, and now I fear I may not be able to save all of your mind and soul as well… but we happen to be now standing in front of a holy grail, aren't we? My family helped create this thing, so I can destroy it too. But, before I do that, let me grant one last wish…" The girl finally walks in front of the glowing sword, standing between it and its target, she asks the wielder one final question: "Emiya Shirou, I, Illyasveil von Einzbern, ask of you, do you have a wish?"

The man stirs, that name has ignited one last spark of life within him, all he can think of at this moment is a purple haired girl, and a promise to see the sakuras together… "I see… a wish to live, for love… then I will grant it." As if reading his mind, Illya smiles, relieved. She steps away, walking backwards toward the grail… "I'm glad… Your soul… is not too far gone… but it is still fragmented… some memories will inevitably be lost to you, but all the times you spent with her are vivid enough to remain. Now, for the first and last time since the creation of this grail, let the great 3rd true magic be performed once more!"

As the girl, wearing the Einzbern family's Dress of Heaven, steps back one final time into the light of her family's greatest creation, the statue of swords once known as Emiya Shirou somehow musters the ability to cry out: "Illya… Illya… Nee-san(Sister)…!"

"Haha, I'm glad I was able to save you at the end, Onii-chan(little brother)… say hi to Sakura and Rin for me, okay?"

With those parting words, the world around them burst into brightness, and a bright red gem shattered. A pillar of light ascended into the heavens above Mt. Enzo, and far away, a purple-haired woman and a pair of sisters watched on fearing for the one who had stayed behind.

Many months later…

A red-haired boy sits in the park, sakura blossoms blooming around him, a purple haired girl with a ribbon in her hair at his side. His current body is not his original, merely a highly advanced copy, inhabited by his miraculously revived soul, yet this was not without a cost. He can no longer remember his father, nor the dream passed down to him at the moment of the man's passing. Is this a blessing, or a loss? Those around him cannot decide.

Yet, these memories were not destroyed, merely part of the soul fragments already lost to the void before Illya arrived to salvage what was left. These soul fragments were not the only ones… for the being now only known as Archer had cast off soul fragments of his own as well… and not just the one from this universe. And thus a second miracle occurred: these collection of fragments were enough to reconstitute a rebirth of a newborn soul. This merged soul, of countless battle experiences and yet also a childhood dream, fell through the kaleidoscope of worlds… and eventually reincarnated into a new world.

A world… needing a Protector of Humanity.