I still remember, with perfect clarity, the emotion I felt when I first welcomed King Arthur home.
"King Arthur! Our great King Arthur!"
"The Nameless King!"
"Please bring peace to Britannia!"
The King's triumphant return.
The King had won the battle and returned to the royal capital of Camelot, accompanied by the Knights of the Round Table who served him.
Men and women, young and old, every citizen had gathered along both sides of the street, cheering joyfully and singing the praises of the great King and his Knights.
Brave, ruthless, steadfast, unyielding.
Seeing that royal majesty for the first time in her life left the young girl deeply shaken from the bottom of her heart.
"Father... he's completely different from usual..."
"That's right, Mordred. That is who your father truly is. Our King and Savior."
Morgan stood atop the white chalk walls, speaking as she rested a hand on the girl's shoulder.
Mordred looked up and saw that the Fairy Queen, famed for her aloofness and cruelty, was gazing at her husband in rapture, her eyes filled with passion and love.
The girl was left speechless.
Until then, the father she knew had been far gentler and more approachable.
He liked cooking and doing housework, and he was good at fixing broken things.
His relationships with women were a mess. Even with two wives, admirers still flocked to him, and he had angered her mother more than once because of it.
He would cheat when playing games with his daughter, then make excuses when he was caught.
Mordred simply could not connect that father with the radiant King who had saved Britannia.
Yet as she was swept up in the near-fanatical cheers around her, the girl gradually came to understand.
Her father was a perfect, complete hero.
Mordred thought that she would likely never catch up to her father's back in her entire life. No matter how hard she tried, she would never be able to recreate the splendor of this day.
So she decided to serve that King.
I will become the King's shadow, the one who goes where his sword points and strikes down the impure.
With that thought in mind, Mordred tried to burn his heroic figure into her eyes.
So that she would never forget the sight of this day, she opened her eyes as wide as she could.
"Hey! Look over there...!"
"Oh... Is that girl the one from the legends!?"
Suddenly, the nearby crowd's chatter reached her ears.
Just as she was about to listen more closely and find out who they were talking about, every citizen present erupted into thunderous cheers.
"Look! It's Her Royal Highness Princess Artoria!"
"The daughter of the King and Guinevere! The disciple taught personally by the Sage Merlin!"
"She followed her father and Professor onto the battlefield at such a young age, and they say she even won glory in the war against the Usurper King Vortigern!"
"How graceful and lovely she is. She's like a white lily blooming on the battlefield...!"
Artoria.
Mordred turned toward the crowd's gaze as if she had been struck by lightning.
The pure-white girl who had drawn every eye in the crowd was none other than her younger sister, Artoria Lily.
"Hehehehe... Well now, Lily, it looks like you've stolen the people's attention.
Not only are you adorable, you're talented too... Give it a few more years, and you'll take my place as the 'woman by the King's side'~"
Merlin, walking behind King Arthur, spoke to the girl beside her.
"Please don't tease me, Professor."
Lily's delicate brows drew together as she said, "I'm still only an Apprentice Knight. I'm nowhere near the level of a Sir.
My technique goes without saying, and even my spirit has yet to be properly tempered.
How could someone as immature as me possibly replace you, the one who supports Father?"
"Huhuhu. So that means you do want to replace me, then?"
The girl clenched her teeth. "Uuuuu... If you keep teasing me, I'm going to tell Father!"
"What is it? Does Lily have something to say to me?"
"F-Father!"
The red-haired young man slowed his pace and came closer to the Court Magus and the girl.
"Listen, Arthur..."
The female Magus grinned wickedly. "Lily says she's going to defeat me and become the person who stands by her father's side to support him. Isn't that frightening?"
"Wait, I never said that."
"Oh? Is that so, Lily?"
The moment her eyes met King Arthur's, the girl's protest caught in her throat, and her cheeks flushed bright red.
Not wanting to disappoint him, Lily nodded in embarrassment and bitterly swallowed her Professor's joke.
"I see. That's a fine ambition. I'm proud of you."
"Fa... Father♡"
"By the way, Lily... if you want to become an outstanding Sir, you should start with small acts within your reach."
"Small acts...?"
The girl tilted her head in confusion, and the King winked at her.
"Wave to the people. I'm sure they'll be delighted."
The moment Lily followed her father's advice and waved to the citizens lining both sides of the road, an outpouring of cheers erupted.
Though it could not compare to the reception given to King Arthur, it was still a roar like a crashing tide.
Standing atop Camelot and watching from afar, Mordred was dumbfounded.
What shocked the girl most was the tender gaze her father turned toward her younger sister.
She had once believed that her father would only ever show that expression to her.
Mordred's mother was the Fairy Queen Morgan, King Arthur's most beloved woman, and she also possessed the Island's Power, the symbol of the Britannian royal bloodline.
Compared to Artoria Lily, who had been born from a political marriage, Mordred's birth was far nobler.
So when people said that Mordred was King Arthur's most beloved daughter, she had accepted it as only natural.
Mordred had always tried hard to be a good older sister.
When Lily was little, she was terribly timid, so on stormy nights Mordred would always step forward and comfort her younger sister.
Mordred had resolved to be a good older sister partly because she wanted her parents' praise, and partly because...
It would have been a lie to say she had never felt superior to her younger sister.
Yet at some point, that frail girl, that younger sister who had always hidden behind her, had reached Father's side before she did.
The sight filled Mordred's chest with an unease she could not shake.
It was as though the dream she had just resolved to chase lay ahead of her, only for an insurmountable mountain to suddenly appear in her path.
Anyone but her. I absolutely cannot lose to her. I refuse to lose.
At that moment, Mordred thought that with fierce conviction.
...
...
Years passed, and both Mordred and Artoria turned fifteen.
Ever since that triumphal parade, Mordred had changed as if she had become someone else.
She resolved to surpass her younger sister and become the person closest to her father, King Arthur.
Mordred began refusing to wear the dresses the maids prepared for her.
Lily always wore the light, fluttering dresses Merlin prepared for her, but Mordred had no need for them.
She refused to let anyone see her as a woman.
Wasn't that only natural?
After all, I'm going to become the knight who serves as King Arthur's shadow!
Mordred thought so as if it were only obvious.
Ignoring her parents' attempts to dissuade her, Mordred applied to join the Round Table and eventually became a Sir of Camelot.
The girl believed this was the only way she could draw closer to her father.
It was the hardest road.
Not approaching her father as his daughter, but approaching her father as a Knight serving her King.
Fortunately, Mordred had inherited her father's talent for battle and her mother's island's Mystery.
She cut her way through battle after battle, gradually making a name for herself.
People no longer called her "Princess," but "Mordred, Knight of the Crimson Lightning."
On the other hand, there were also sharp voices of criticism.
The people believed Mordred's way of fighting was too rough and too savage.
Forget living up to the image of Camelot's royal family. Even among the Knights of the Round Table, there was no one else like her.
The girl paid no attention to those criticisms.
In her eyes, victory was everything.
If it meant winning, then slashing with a sword, kicking, beating enemies with her fists, or even biting them with her teeth were all acceptable.
This is my mission.
Only I can bring glory to Father!
Compared to the eldest daughter, who inspired both praise and criticism, the younger sister, Artoria, was clearly the one who won the people's hearts.
If Mordred had inherited the King's talent for battle, then Lily could be said to have inherited the King's charisma as a leader.
She was a natural leader. She could even be called an idol.
Lily's appearance was like an endearing white lily, and her emerald eyes seemed to shine with a hopeful light that stirred people's hearts.
Of course, Mordred knew very well that she could never compare to her younger sister when it came to winning people over.
But that was fine.
None of that mattered.
What could those ignorant fools who could not even read possibly understand?
I'm not fighting for people who can't understand me. I'm fighting only for Father!
Father is definitely watching.
My efforts, my excellence, my sincerity, my everything.
Father will definitely see it all clearly.
That's right, just like when I was little.
Whenever I beat my younger sister in a race, Father would always praise me gently.
Whenever I accidentally did something wrong, Father would always comfort me patiently.
In this world, the first person to acknowledge me... was Father.
And his acknowledgment is the only one I need.
Other people's opinions mean nothing. All of them put together still can't compare to Father.
My glory and my honor belong to Father alone.
Of course, one day, I will inherit everything from Father too.
Although Mordred and Artoria had become rivals, their relationship did not worsen because of it.
A few years earlier, Mordred had gone to Lily and issued a challenge with fierce momentum.
"Artoria, you've been standing out quite a lot lately. Don't tell me a few compliments from everyone around you have gone to your head?
Hmph... Don't get too pleased with yourself just yet. My era comes next!
I'll prove to everyone that I'm the finest child of King Arthur!
There's no such thing as an older sister who loses to her younger sister!"
Mordred had thought Lily would act timidly, just as she had when they were children. Instead...
"Um... Could this mean... that you acknowledge me too, Mordred Onee-sama?"
"Huh? Ah... That's not what I meant..."
"All right~ I understand! Although you are... no, precisely because you are the Mordred Onee-sama I respect most.
I accept your challenge! Onee-sama, let's compete fair and square, and support Father's cause together!"
It truly startled her.
The sincere, confident smile on Artoria's face made Mordred feel afraid.
She had planned to give Lily a harsh scolding if the girl lost her nerve and said something like, "How could I ever compare to Mordred Onee-sama?"
But Lily had already changed completely. She no longer needed her older sister to push her forward.
Mordred curled the corner of her mouth. "You've got nerve, Artoria...
Since you've gone that far, I'll make you lose so thoroughly that you'll have no choice but to accept it.
When that happens, don't go crying to Father, all right?"
"Right back at you, Mordred Onee-sama... Have you stopped crying in Father's arms yet?"
The two sisters shared a knowing smile.
The days that followed were like a storm.
Mordred and Lily each worked hard in their own way.
The healthy rivalry between the two princesses breathed new life into Camelot.
Although Mordred did not have as many devoted supporters as Artoria, she had also gathered a large number of followers of her own.
People were moved by the spirit of the King's child charging at the very front, and one after another, they began to follow her.
Even Mordred herself never realized that she too had inherited the charisma of leadership from the father she revered. Otherwise, she could never have gained so much support.
But one day, that balance was broken.
The news that Father had given Artoria [Sword of Selection (Caliburn)] was secretly passed to Mordred by one of her attendants.
Impossible!
Mordred rejected it instinctively.
[Sword of Selection (Caliburn)] was the origin of the legend of King Arthur, as well as one of the symbols of the King of Knights.
How could Father give something that important to Lily?
Unless he had already decided to pass the throne to Artoria.
At that thought, Mordred almost stopped breathing.
Though she could not believe it, she still went to see Artoria.
And then she saw it, Father's golden sword, proudly worn at her younger sister's waist.
"..."
Mordred ignored Artoria when she tried to speak to her and fled.
She ran to her father's office deep within Camelot, intending to demand an answer from him.
Why...?
What am I supposed to ask?
Father believes Artoria is the better heir, so he gave her the Sword of Selection.
That was Father's decision. As a Knight, and as his daughter, she had no right to object.
Was the frustration and resentment in her chest a sense of injustice?
No... no, that was not it.
This dark feeling was jealousy. It was inferiority.
Only today did Mordred finally understand that the feelings she held toward her younger sister were, in truth, an inferiority complex.
What did "my own way of fighting" even mean?
It was nothing but self-deception.
The truth was, this was the only way you knew how to fight.
You cannot shine like Father or Artoria.
You cannot inspire people the way they do, so all you can do is charge to the very front of the battlefield and spill your blood.
In the Kingdom of Britannia, countless powerful Knights had come in admiration of Arthur's name.
Too many heroes and strong warriors had gathered around the King.
But there was only one person who could inspire the people and lead them as the King did.
That was something Mordred could never achieve, no matter how hard she tried.
That was the proof that Artoria was the true heir to Britannia.
By the time Mordred reached the office door, the anger in her heart had already turned into despair.
"Hm? Mordred... what brings you here?"
King Arthur came forward happily when he saw his daughter.
"Father..."
Mordred bit her lip, unable to raise her head and meet his eyes.
"What's wrong?"
The red-haired young man frowned in confusion. "Did someone bully you? Hahaha, I'm only joking...
Who in all of Britannia could possibly bully our Mordred?
Even Morgan, the Witch of Britain, often gets so angry at her daughter that she comes running to me to vent.
Ah, don't tell your mother I said that just now, all right? Otherwise I'm finished."
Mordred said nothing.
"Oh, right. You came at the perfect time. There's something I wanted to give you."
As he said that, Arthur opened the long box resting on the desk.
Inside lay a beautifully decorated silver sword.
Its blade seemed to carry warmth, and a powerful aura of True Ether rippled from it. It was an incredible magic sword.
"What is this?"
"[Magic Sword Clarent]. You've heard the rumors about it too, haven't you, Mordred?
It's a trophy I seized after fighting the Gallic governor when the Roman Empire invaded Britannia."
"Clarent is the sword that symbolizes Gallic kingship, but since I've taken it, I have no reason to give it back."
King Arthur carefully stroked the magnificent silver sword, then looked into Mordred's eyes and said,
"I intend to entrust it to you. From now on, it will represent the sovereignty of Britannia."
Note: I retconned this. Previously, Artoria in this world was written as a Magus, but now I've changed the setting to Lily.