Come to think of it, Shirou had only recently learned about a certain "shortcut" for Mana replenishment from Lady Avalon.
At the time, he had been struggling over how to supply Mana to Assassin, and she had mischievously leaned in and whispered the method into his ear.
A man and a woman can establish a magical conduit simply through physical intimacy.
A man's semen is the purest crystallization of Mana.
These were apparently the most basic pieces of common knowledge in the world of Magecraft, yet Shirou knew nothing about them.
Because in the Fairy Kingdom, Morgan had never taught him any of this.
Even so, while he slept, those people had somehow gotten their hands on Mana supplements, and had even fought over them…
Thinking back on it now, something about it felt very off.
"…Mm!"
Shirou felt his thoughts grow muddled. Out of the corner of his eye, he glanced at Lady Avalon, who had been silent the whole time.
A faint blush colored her small, delicate face, making her look even more alluring than usual.
An inexplicable dryness rose in Shirou's throat, and he hurriedly suppressed the restlessness in his chest.
"By the way, Avalon-nee-san… you should know some Magecraft, right. The kind that lets you draw Mana from others?"
"Ah, yes… I do."
Lady Avalon lowered her head and replied absentmindedly.
Of course she did.
At the end of the day, exchanging bodily fluids for Mana was something only third-rate Magi would rely on. A Magus of Lady Avalon's level had no need for such methods.
Honestly… what was I even worrying about, or expecting?
Shirou let out a quiet sigh of relief.
At that moment, Lady Avalon spoke softly, her cheeks tinged red.
"I-I do have Magecraft for supplying Mana… but it requires cooperation from the other party. Master's Magecraft ability is too poor, so it's not possible."
"Huh?! Am I really that bad?!"
"Mm."
Lady Avalon answered with firm certainty.
"Establishing a magical conduit is an extremely complex process. A single mistake can cause severe backlash. For a third-rate Magus like Master, the risk is far too great."
"I see…"
"That's right… so…"
Shirou noticed her slender, pale throat move slightly as she swallowed.
"I told you before, didn't I? If Master wants to supply Mana to a female Servant, then just holding her is enough…
Ugh… it's very simple, right?
Even a third-rate Magus like Master can manage that."
"You did say that…"
Shirou nodded.
"But could you stop calling me third-rate all the time? It really hurts."
Lady Avalon muttered in protest,
"B-because Master really is third-rate…!"
Damn it…
Having been put down nonstop, Shirou felt that strange restlessness in his chest growing stronger.
"Master… you want to stop the Holy Grail and Saber, don't you?"
"Mm. Of course I do."
Lady Avalon continued,
"Now that the Dead Count Shapeshifter's Command Spell has been destroyed, if Master wants to fight Saber, you'll have to rely on my power.
So there's no time to hesitate. There's only one thing left to do.
What are you waiting for?
I don't want Master to fail at the very end because of me…"
Shirou felt his face heating up, his thoughts growing increasingly chaotic.
"But… if we do that, Avalon-nee-san…
No… I can't! I can't go that far, using any means necessary just to win!"
"Master… no, Shirou…"
"?"
His hand was suddenly grasped by another, larger yet more slender hand.
Startled, Shirou looked up.
Lady Avalon was staring at him, her face flushed, her breathing uneven.
"What makes you think I'd be unwilling?"
"Uh…"
Shirou's rationality began to dissolve.
With a deeply bashful expression, Lady Avalon murmured softly,
"I'm not unwilling at all… if it's with Master♡"
Shirou: "......"
A faint, pleasant fragrance drifted into his nose.
Lady Avalon leaned even closer.
Under the starlight of the late-night forest, her flawless face looked almost unreal.
Snow-white skin, slender arms, shimmering silver hair, a waist so slim it could be held in one hand, smooth, well-shaped legs, and a softly curved chest…
And in Shirou's hands still lingered the sensation from when he had carried her into the woods earlier.
It wasn't his imagination. Lady Avalon's body was even softer than a human's.
If even her body felt this soft, he couldn't help but wonder just how it would feel inside…
"Hah…"
Shirou's breathing had grown so heavy it no longer sounded like that of a child.
There was also her unbelievably light weight.
He didn't understand the reason, but Lady Avalon weighed less than half of a normal adult.
She's even lighter than me…
The moment that realization hit him, Shirou felt a surge of excitement.
It was like telling himself this. She was an adult woman whom even someone like him could easily overpower…
"What's wrong, Master… are you really that resistant… do you dislike holding me that much…"
Lady Avalon watched his expression with faint dissatisfaction.
"N-no… that's not it… Avalon-nee-san…"
"Hehe… it looks like Master has accepted it, then. We don't have much time, so let's begin."
With one hand pinning Shirou's wrist and the other resting against his cheek, Lady Avalon slowly leaned in.
"W-wait… this is my first time!" Shirou shouted.
"It's fine, it's my first time too… I won't let Master be at a disadvantage."
"N-no, that's not the problem.!"
Before he could finish, Lady Avalon sealed his protest with her soft, delicate lips.
"............"
Silence stretched on for more than ten seconds.
Then, with a long, satisfied sigh from Lady Avalon, the kiss finally ended.
Even after it was over, the sweetness and warmth of her lips still lingered vividly in Shirou's mind.
Meanwhile, something within Lady Avalon seemed to have been switched on by that kiss, a radiant light beginning to shimmer in her eyes.
"Hehe… let's continue… Master♡"
Smiling with a soft, alluring charm, the female Magus dispelled the clothes woven from Mana.
The instant her dreamlike form was revealed before him, Shirou's thoughts and senses were completely overwhelmed.
He could say with absolute certainty. There could not possibly be anything in this world more beautiful than the body before him.
Yet that perfection didn't inspire reverence.
Instead…
It made him want to leave his mark on her.
It made him want to claim her as his own.
"Avalon-nee…"
The silver-haired Succubus pressed a slender finger against his lips, stopping him from speaking further.
"Just for tonight, you can call me 'teacher,' you know?"
…
…
"........."
Shirou sat on the stone steps along the mountain path, quietly gazing up at the moonlight.
After the second round, Lady Avalon had driven him outside.
She said that although the Mana transfer was complete, she herself had been left in a complete mess by her Master. If she went out like that, anyone would notice immediately.
So Shirou had no choice but to wait outside.
As he sat there in silence, the memories of what had just happened replayed in his mind.
It had been so overwhelmingly pleasant that it felt like he had released eight years' worth all at once…
"…Mm."
Shirou shook his head.
The final battle was about to begin. If he kept indulging in Lady Avalon's warmth, it could cost him his life.
Now wasn't the time to think about that.
Lady Avalon had made such a sacrifice for him. If nothing else, he had to win in the end to repay her.
Shirou took a deep breath of the cold night air and slapped his cheeks.
Then he began to think about the upcoming fight against Saber.
His opponent was a wielder of the Holy Sword with overwhelming firepower and effectively limitless Mana.
Without the Dead Count Shapeshifter's Command Spell, Shirou couldn't use Unlimited Blade Works the way he had against Gilgamesh.
"Lake of the Holy Sword"… he had already shown that once in front of Saber. She would likely break through it without difficulty.
So all he could rely on was projected swords…
"Trace on."
With the incantation, a silver longsword appeared in Shirou's hand.
An ordinary sword wouldn't be enough to defeat Saber… Shirou let out a quiet sigh.
"You've been sighing for a while now. Master may be young, but sighing all the time isn't a good habit."
Shirou turned around and saw Lady Avalon standing behind him.
"Ah… right. Master isn't a child anymore, he's a proper man now~"
Lady Avalon covered her mouth and let out a soft laugh.
Under normal circumstances, Shirou would have argued back fiercely, but today, he couldn't bring himself to say a single word in response.
Lady Avalon had already straightened her clothes and hair, looking as though nothing had happened at all.
"I'll apply Reinforcement Magecraft to you, Master."
"Yeah, I'm counting on you."
Lady Avalon put away her playful expression and began quietly chanting a spell-like incantation.
Reinforcement Magecraft began to take hold over Shirou's body.
It functioned like a protective film, enhancing his endurance while absorbing incoming damage. A form of Age of Gods Magecraft that could be called an invisible suit of magical armor.
"I wish I could use Magecraft like that," Shirou said.
"Hehe, Master has his own strengths too."
Lady Avalon replied casually as she began applying Magecraft to enhance Shirou's strength.
"Besides, our opponent is Saber. This level of Magecraft won't hold up for more than a few hits."
"So this is basically just for peace of mind?"
Then didn't we just do all that Mana transfer for nothing… Shirou swallowed that complaint.
"What matters is your mindset. Your mindset."
Puffing her cheeks slightly, Lady Avalon added, "Do you feel more confident now?"
"Yeah."
Shirou nodded.
But that confidence didn't come from the reinforcement Magecraft. It came from what had just happened between him and Lady Avalon…
Looking at her face, he couldn't help recalling the alluring expression she had when she was on top of him earlier.
"…Ugh."
Shirou hurriedly shook his head. The battle was about to begin. He couldn't afford to react like that again.
Just then, his gaze drifted to the female Magus's chest.
Did she erase the bite marks I left with Magecraft too…
"Why is your face red again?"
Lady Avalon crouched down beside him.
"It's nothing!"
Shirou forcefully pushed away her reaching hand and stood up.
"Let's go."
"Mm-hmm."
Without another word, the two began climbing the steps leading to Ryuudou Temple.
After walking for a while, one of them broke the silence.
"Hey, Master."
"What is it?"
"Did it feel good?"
"............Yeah."
Hearing that, Lady Avalon smiled happily.
Shirou turned his face slightly away.
"If we both make it through tonight… then…"
"Avalon-nee-san, would you stay and live with me from now on?"
Once the Holy Grail is destroyed, Servants return to the Throne of Heroes.
Shirou knew that perfectly well.
But for some reason, he felt that Lady Avalon might be able to remain in this era.
So, while he still had the chance, he said what was on his mind.
"......"
Lady Avalon froze.
The composure on her face broke as a blush spread across her cheeks again. She stared blankly at the boy.
"Um… could this be…"
Shirou nodded earnestly.
Though they had known each other for less than a week, to him, Avalon-nee-san had already become an irreplaceable presence, like family.
So—
Lady Avalon covered her mouth in astonishment.
"Master, are you asking me to be your long-term fling?"
"That's not it! Why would you think that?!"
…
…
After about five minutes of walking, the two arrived at Ryuudou Temple.
The temple, said to be several hundred years old and even older than the Holy Grail War itself, was shrouded in an ominous aura of Mana.
Shirou and Lady Avalon moved forward cautiously, step by step.
Passing through the ancient temple gate, they were greeted by a wide, open courtyard.
Despite it being night, and with no lights lit anywhere in the temple, the surroundings were as bright as day.
Right there, even without ever having seen it before, Shirou recognized it instantly.
That was it.
The Holy Grail.
A golden cup suspended more than ten meters above the ground, existing in midair.
It wasn't floating. It simply existed there.
There was no mechanism, no device holding it up.
Densely compressed Mana, an invisible vortex, flames without fire…
As these impressions surfaced one after another in Shirou's mind, he knew without a doubt that it was the Holy Grail.
At the same time, he understood why the temple was so bright in the dead of night.
The light came from the Mana radiating off the Holy Grail itself.
Without a word, Shirou projected the "Blades of Chaos" into his hand.
At that moment—
"So the insects drawn by the Holy Grail's radiance have finally arrived. You've kept me waiting long enough."
Shirou turned toward the voice.
What he saw was Saber, clad in pitch black, so changed she looked like a different person.
And beside her stood a red-haired girl.