Emiya Shirou and Tohsaka Rin first agreed to a temporary ceasefire. And then, the two talked and discussed their mutual misunderstandings...
"So... in conclusion, Shirou and Rin each fought a Servant taking the other's form. I also fought a Servant in Rin's form."
"That's right... What exactly is going on, is it some Servant's Noble Phantasm?"
"... I have one person in mind, but still... I think we need to watch the situation a bit more."
"You have someone in mind?"
Rin asked Saber, but... Saber recalled a certain battle from the past and kept her mouth shut for now.
Since Rin was ultimately from a different faction, and Shirou was a novice Master, she couldn't speak carelessly.
Now that the misunderstanding was cleared up, the group decided to go to the church to get a detailed explanation from Emiya Shirou and confirm his intention to participate.
Walking through the night streets, passing through a desolate alley...
[Rin, Servant.]
"Servant...?"
Upon receiving Archer's telepathic message, Rin headed inside the alley, where her classmate Mitsuzuri was, having been bitten by a Rider with an eyepatch and fallen unconscious.
"Mitsuzuri...?"
Shirou, who discovered her along with Rin, tried to run to her, but Saber blocked his way... Saber intuitively felt something.
"The enemy is one... I'll leave this place to you."
"Haa?"
"There is another enemy."
"... Got it."
Before entering the alley, Saber took Shirou and headed toward the place she felt with her intuition, while Rin entered the alley with Archer.
"As expected, Tohsaka. You became a Master, huh?"
"Shinji..."
And Matou Shinji revealed himself coming down the stairs inside the alley. In his hand, the Tome of False Attendant fluttered open.
Along with Shinji's lengthy ambitions, Rider moved, and the battle between Archer and Rider began.
Meanwhile, Saber and Shirou arrived at another alley that felt ominous.
"Hmm~♪ Huh-hmm~♪"
There, they saw a little girl with a backpack, hopping across puddles gathered in the alley.
"That girl..."
Shirou realized she looked exactly like the girl he passed by on his way home late one night recently, and Saber frowned as soon as she saw her.
"You came? Saber, and big brother."
"You are, who...? Last time you called me big brother too?"
"... Yeah, I did. You summoned her after all, huh? Congratulations, now big brother is a Master too."
"Ilyasviel. You're still in Fuyuki?"
"Hueh? ... Don't tell me Saber, you have memories? That's weird... Why would that be? Is Saber special by her very existence? Maybe it's fate's mischief..."
"Please answer seriously."
"Saber? You know each other...?"
Hehe... The smiling Illya then greeted them.
"I'm Illya. Ilyasviel von Einzbern. Nice to meet you, big brother. Now, shall I show you my power?"
A sparkling wand was in Illya's hand, and as she twirled it once, light emanated from the wand and enveloped her.
"Light, become a spiral!"
Fwaaaaaah!!!
".....Huh?"
"Magical Girl! Prisma☆Illya makes her appearance!"
".......?"
For a moment, Shirou couldn't process the scene before his eyes. The girl suddenly became a magical girl. Even for someone who dreams of being a champion of justice, this was a phenomenon causing enough cognitive dissonance.
But Saber already knew, so without concern, she charged at Illya. However, Illya quickly flew upward.
"Feuer~!"
She fired a mana cannon, and Saber, ignoring it with her Magic Resistance, made a great leap to reach Illya's height and immediately swung her sword.
Clang!!!
[Ugyaaah!!! It hurts, Illya-san!]
"Sorry Ruby~ The barrier just broke~!"
She tried to deploy a barrier to block, but against Servant-level opponents, Illya's attacks were mostly useless.
[I really feel like Ruby-chan here is too weak...!]
"That's true... But, not anymore, right? Now, we're strong too, right?"
[That's right... After reaching Bond Level 10, we got it back.]
"..."
Saber listened to Illya and Ruby's conversation and noticed the card case on her thigh. For some reason, Saber felt an ominous and threatening sensation and tried to hurry the fight, but Illya quickly descended to the ground. Then she pulled a card from the card case.
Saber quickly ran to stop her, but...
"Saber! Emiya-kun! Are you okay!?"
Rin and Archer, who had defeated Rider and came running after Shinji, who fled with the Tome of False Attendant burning. Illya pouted her lips as if disappointed.
"No choice, I guess... I wanted to use it."
"Ilyasviel!"
"Unfortunately... We'll meet again soon, big brother. At that time..."
"I'll show you my real power, okay?"
Grinning, she then turned into light and disappeared. Saber's sword cut through the air where the girl who had escaped had been, and she clicked her tongue.
"Again, it ended like this..."
"What was that just now! Who were you fighting with!"
"... A magical girl?"
"Haa? Have you been drinking or something?"
"That can't be... Fuji-nee sometimes offers, but I don't drink..."
Shirou looked at the spot where Illya had been, resigned to waiting for another time, and headed to the church.
Shirou met Kotomine Kirei, the church's supervisor, listened to his story, and decided to fight as a Holy Grail War participant.
After leaving the church, Shirou and Saber renewed their partnership... Then, the church's iron gate closed... and two figures appeared from within the fog.
"Hello, big brother. This is the second time we meet like this, right? I'm Illya. Ilyasviel von Einzbern. Einzbern, you know, right?"
"Now you've even brought a Berserker... I truly don't know where this ends, Ilyasviel."
"?"
Illya felt something odd about Saber's words...
"Be careful, Tohsaka. That girl, she's a magical girl!"
".... Huh? Are you serious?"
"Haa...?"
[What is that guy saying...?]
At Shirou's words, Rin was dumbfounded, Illya was momentarily stunned by what she heard, and Archer was horrified at what his past self was saying like some madman.
"It's the truth, Rin. At least it seemed like she was hiding her power until now."
"Right, definitely... Magical Girl Prisma☆Illya! That's what she said!"
"... Hey, you're trying to provoke me right now, right?"
Illya was dumbfounded and genuinely annoyed by the ridiculous words she was hearing for the first time in her life. Of course, Shirou and Saber were serious, and because of that, Rin and Archer were confused to the point of not knowing which side was telling the truth.
"Ahh, what a spectacle. Now kill each other...!"
"But, it's a shame I couldn't use the Class Card..."
"You can use it next time, right? Illya. Anyway... this is just the beginning. Let's go home quickly. Sakura will be waiting."
"Okay~"
Well, the developments after this probably won't be much different. But... if this follows this route, would it be Heaven's Feel? Doesn't matter. After all, I'm the one holding the cards.