Three days into their journey.
Inside the carriage racing down a forest road in Britain, a tension unlike any ordinary adventuring party hung in the air.
This wasn’t caution against magical beasts or bandits.
It was a fierce game of cat-and-mouse—no, a full-blown territorial war—over who would get to sit next to Kay.
"It’s cramped. Move over," Artoria Alter grunted, shoving the person beside her with her hip. Her black armor clattered with the movement.
"How rude. You're wrinkling my armor. Besides, this space is my designated territory," Artoria Lancer countered, holding her ground with elegant firmness.
The carriage had been summoned by Merlin’s magecraft and was surprisingly spacious—large enough to comfortably fit ten grown men.
Yet right now, it felt as if it were about to burst at the seams.
The reason was simple.
Eight girls, one man, and a baby were all vying to remain within a thirty-centimeter radius of Kay.
The population density had reached a breaking point.
"Sigh... would you girls mind sitting a bit further away? I'm roasting over here."
The man at the center of the storm, Kay, was currently squeezed into a corner.
Strapped to his back in a sling was baby Gareth, and in his hands, he clutched a milk bottle, a diaper bag, and a pouch of snacks.
"Brother, are you hot? Shall I fan you?" Lily asked, smiling like a blooming flower as she reached out.
"No, I'll cool you down with some ice magecraft..." Artoria Caster began, raising her staff, but Artoria X Alter cut her off.
"Force Wind."
Whooooosh!
A localized gale erupted inside the carriage. Kay’s hair whipped around wildly like strands of seaweed.
"Gah! It's freezing! You'll give the baby a cold! Stop it!"
Kay yelped, instinctively shielding Gareth from the wind.
While the girls glared at one another, competing to see who could care for Kay the best, Kay's mind was focused on only one thing.
*Please... just let Gareth stay asleep.*
Because if the little one started crying, the task of soothing him would fall entirely on Kay's shoulders.
Around noon, the group decided to take a break in a forest clearing.
Merlin, claiming he was exhausted, promptly retreated to the shade of a tree.
The girls stepped out of the carriage to stretch their stiff limbs and inspect their weapons.
That was when it happened.
Crack! Thud!
Trees snapped like toothpicks as a massive shadow loomed over them.
It was a composite magical beast with the head of a lion, the body of a goat, and the tail of a snake.
A Chimera.
Grrrrrr!
The Chimera’s roar shook the very earth. Its overwhelming pressure would have sent any ordinary knight fleeing in terror.
But to this "childcare expedition," it was nothing more than an annoying intruder.
"...Tch. So noisy," Artoria Alter muttered, drawing her sword with an irritated snap.
"Brother is trying to let the baby sleep. Do you have no shame?"
"This beast is utterly clueless. How dare it disturb Brother's rest." Artoria Lancer and Artoria Lancer Alter leveled their Rhongomyniad spears. Their gazes were far more predatory than the monster's.
In an instant, all eight girls entered a combat stance.
Their eyes weren't those of cold warriors hunting prey, but of teenage girls desperate to show off their strength to their big brother.
*Now's my chance! Time to show Brother how strong I am!*
"I'll handle this! Brother, watch me!" Artoria leapt forward first.
"No, I'll be the one to show him the power of Excalibur! Get out of the way!"
Artoria X charged ahead, dual-wielding her blades.
"Move aside! You shall be the sacrifice for my magecraft!"
Artoria Caster began her incantation.
K-BOOM!
Eight ultimate attacks detonated simultaneously.
The Chimera didn't even have time to scream.
Slashed by holy swords, pierced by holy spears, hammered by magical bombardments, seared by beam blades, and strangled by force... in a heartbeat, the beast was reduced to mincemeat.
As the dust settled, the girls turned back in unison.
Their eyes were wide with anticipation, eight pairs of pupils sparkling with hope.
"Brother! Did you see that?"
"I got the last hit! Did you see me?"
But Kay wasn't looking at them.
He was too busy cooing at Gareth, who had been woken up by the noise.
"There, there, our little Gareth. You didn't wake up, did you? Such a good baby. Who was making all that noise, hm?"
Kay gently patted Gareth's back as he walked toward the remains of the Chimera.
The girls puffed out their chests, waiting for praise like puppies longing for a treat.
However, the words that left Kay's mouth were far from complimentary.
"Hey, you girls... didn't you hit it a bit too hard?"
"...What?" Artoria asked, bewildered.
Kay clicked his tongue as he looked at the pulverized remains.
"Look at this. The tail is snake meat, which should be chewy, and the lion ribs would have made a perfect steak. But since you've minced it all, I can only make meatballs now."
He sounded genuinely devastated.
"And you burned it too much. Who used the beam sword? You've sucked all the juices right out of the meat."
"...."
The girls' shoulders slumped in utter defeat.
They had wielded the holy swords that would save Britain, only to be criticized for their poor butchery skills.
Yet, even this obliviousness was part of his charm.
*As expected of Brother. To see a magical beast and immediately think of it as ingredients... so dependable, so domestic.*
Their infatuation was absolute.
"Next time, catch it more gently so I can carve it by the cut. Got it?"
"Yes..."
Though they were crestfallen, they didn't complain. After all, this was all so he could cook them a delicious meal.
That evening, Kay began cooking with the Chimera meat as promised.
Since the meat was already minced, he had no choice in the menu.
The dishes were Chimera meatball soup and sautéed tail meat.
Using the pea-soy sauce he had prepared previously as a base, a heavenly aroma began to waft through the forest.
"Dinner time!"
As soon as it was time to eat, the war resumed.
Not a war over the food, but a war over the seating.
"Brother, please sit here."
Artoria Lancer spread her cloak on the ground and patted the spot beside her.
"It's my cloak. It's very soft."
"Don't be ridiculous! Kay is sitting next to me!" Artoria Alter yanked Kay's arm.
"Um, I-I'll wipe your mouth for you, Brother!" Lily approached, face flushing red, holding a handkerchief.
Amidst the chaos, Kay nonchalantly picked up a spoon.
Instead of feeding himself, he scooped some potato porridge—made specifically as baby food—and fed it to Gareth in his arms.
"There we go, say 'ahh,' Gareth. Look at you, eating so well."
"...."
The girls' gazes locked onto Gareth.
It was pure jealousy.
They felt pathetic for being jealous of an infant, but they envied the nephew who monopolized Kay's tender gaze and touch.
"It's not fair... I want to be a baby too," Artoria Alter muttered.
"Get a grip on yourself," Artoria scolded, though her own eyes were filled with longing as she looked at Gareth.
Just then, Artoria X Alter crept up behind Kay.
Taking advantage of Kay's focus on the cooking, she used her chopsticks to pick up a meatball and popped it right into his mouth.
"...Mmph?"
Kay turned around in surprise, and Artoria X Alter feigned indifference, adjusting her glasses.
"I was simply checking for poison. You know, acting as the royal food taster."
"...Hey, I made this. Why would there be poison in it?"
Kay grumbled, but he chewed the meatball anyway.
"Tastes good, though."
At those words, the other sisters' eyes lit up like fire.
*She beat us to it?!*
This time, Artoria gathered her courage.
"B-Brother... could you... could you feed me too?"
"Do you not have hands? Eat it yourself." Kay was firm.
"...My hand is injured. From when we caught the Chimera earlier."
It was a blatant lie. She didn't have a single scratch on her. There was no way someone blessed by the holy sword would be injured by a mere Chimera.
But Kay, whether he was humoring her or was truly oblivious, clicked his tongue.
"Tch, you should be more careful. Especially for someone who wants to be king."
Kay picked up a piece of meat and popped it into Artoria's mouth.
"Ahh."
Artoria's face flared bright red.
She couldn't tell if it was the taste of the meat or the taste of love. She chewed with a blissful expression, looking as if she had just conquered the world.
The other sisters couldn't just stand there and watch.
"Me too! I'm injured too! My heart is wounded! Hurry up and feed me!" Artoria X rushed forward with her mouth open.
"My arm won't move, Brother!" Lily acted out, putting on a tearful face.
"I've depleted my mana, so my hands are shaking... I don't have the strength to hold a spoon," Artoria Caster added, letting her staff drop as she swayed.
"Me too! My force is backflowing...!" Artoria X Alter clutched her chest.
Ultimately, Kay, while still carrying Gareth on his back, had to feed each of his eight younger sisters in turn.
"What sin did I commit in my past life... No, what kind of royal table is this? It's a kindergarten! How old are you girls, letting me feed you like this?"
Kay's complaints echoed through the forest.
Despite the grumbling, his movements were careful and his gaze was warm.
"Here, eat up. Eat a lot, grow up quickly, and then become independent."
The girls accepted the food with the happiest expressions imaginable.
*Independent? Never.*
*I'll spend my whole life clinging to this man and mooching off him.*
From his perch in a tree, Merlin watched the scene and shook his head.
"Haha... the future of Britain is truly bright. A whole group of kings collectively regressing to infancy."
That night, the campfire in the forest was louder and sweeter than any royal banquet.
After the meal, while the others wandered the forest to gather supplies, Kay and Artoria Lancer Alter remained at the campsite to look after the baby.
The role of staying by Kay's side had been decided via a game of rock-paper-scissors.
"Listen, there's something I want to tell you."
"W-what is it?"
Seeing Kay's serious expression, Artoria Lancer Alter tensed up instinctively. *Could this be a confession?*
"I saw you all using your power earlier. I've been thinking about this for a while, but you learned how to use your strength from Merlin, right?"
It was a false alarm. Artoria Lancer Alter struggled to hide her disappointment.
"Ah, yes. That's correct."
"Hmm. Is that why? Did he think there was no need to consider the details because you're geniuses? Or does Merlin himself not know?"
"Know what?"
"To my eyes, it feels like there are too many unnecessary elements when you use your power."
"Unnecessary... elements?"
Taught by Merlin, they were indisputably among the strongest in Britain. However, to Kay—who had always been labeled as a man of average talent—their flaws were glaringly obvious.
"Your power is too excessive. From what I've seen, your combat techniques are amazing—far beyond what I could ever replicate. But the problem is the application. Even when you have the optimal posture, you aren't utilizing that power efficiently."
"How do you know that, Brother?"
"Because I can do it. I realized it after crossing the line between life and death countless times."
"Ah..."
Kay had faced death repeatedly since the age of five.
Unlike the geniuses, he was an average man; his floor and ceiling were both lower. Consequently, even in the forests of Tintagel, he had encountered monsters that were terrifying even by his standards. That experience was exactly what had made him strong.
"Even with the same punch or the same stance, the power varies wildly depending on how you control your strength. How you move your muscles, how much pressure you put into your fingers, how you utilize your five senses, and whether your breathing is correct."
"Even breathing...?"
"Breathing is crucial. Humans cannot function without oxygen. The amount of power you can generate changes based on whether you use minimal or maximal breath. You don't know how to draw out maximum power using minimum breath and effort. Perhaps you're such geniuses that he felt it was unnecessary to teach you. Or perhaps Merlin doesn't know. Or..."
"Or?"
"Maybe he wanted you to encounter someone of equal or greater strength and realize it yourself through the trial of growth."
"That's the worst. Couldn't he just teach us?"
"Exactly. It's not like you don't have a teacher, unlike me. Learning through actual combat etches the lesson into your bones, but that's a reckless and painful path. In that sense, he's the worst teacher. Maybe it's because he's not human."
Kay assumed that Merlin couldn't have missed something that even an average person like himself noticed.
But in reality, Merlin truly didn't know.
Because he, too, was a genius. Why bother with "maximum efficiency with minimum effort" when you can just slice everything apart with magecraft or swordsmanship? He had never felt the need for it.
It was precisely because Kay was average that he had realized this.
For geniuses, fighting is simply not that difficult.
This was a realization typically born from immense hardship.
Just as the invincible Heracles grew through his Twelve Labors and various journeys, these things are learned through the heat of battle.
A mage who wasn't a physical fighter, a genius who used a sword simply because it was easier than incantations, and a useless incubus who never stood on the front lines—there was no way Merlin would be familiar with such a field.
"What is this breathing method?"
"By breathing correctly, you circulate vitality throughout your entire body. In the East, they have a concept called 'Ki.' In our terms, it's like circulating mana through the body for maximum efficiency. Through breathing alone, you can increase your strength, become more agile, and harden your body. And by accelerating your heartbeat to move blood faster, you can temporarily draw out explosive power."
"H-how do you do such a thing?"
"Because I've done it. I found that if you just keep trying, it eventually works. Effort is all I have, after all. When you do it, heat begins to flow from the body. And through breathing, you can temporarily expand your muscles. I suppose it's like an adrenaline or testosterone rush?"
"What on earth is that?"
"It's a thing. It's hard to explain. Anyway, my point is this: you are already strong enough, but if you practice using your power efficiently, you'll become twice as strong as you are now. You could learn it while fighting, but I want you to master it before then. I'd rather not see you get hurt."
At Kay's words of concern, Artoria Lancer Alter let out a faint smile. No matter how much things changed or how many new family members arrived, he was still the same brother who cared for them deeply.
Arturia: Dragon breathing first form.