"As I mentioned before, this is most likely Illya from Prisma Illya."
The term "Dream Summon" already reveals a lot. To be honest, the Holy Grail System from that world would be more fitting for Yu-Gi-Oh! card classifications.
"A magical girl? That's something from anime... How could that be? I'm just an ordinary elementary school student," Magical Illya (hereafter referred to as Illya, unless appearing alone) replied weakly from the Battle Zone. She was still fidgeting with her revealing outfit, on the verge of tears, a misty haze already forming in her eyes. "So, could someone please give me some clothes? Please!"
Illya was certain this girl wasn't her. While she also felt shy about overly revealing outfits, she would never be this timid and fragile.
Like a side quest to increase Affection, Jiang You took off his jacket and tossed it to Magical Illya.
"Thank you..."
Magical Illya draped Jiang You's tailcoat over her shoulders. Due to the significant height difference, the coat hung loosely on her like a cloak.
Jiang You had acquired a minor Prisma Illya card locally, a mere scrap that barely increased her Affection.
"Illya from a parallel world..."
Rin Tohsaka wasn't particularly surprised. Her family had inherited a portion of Kaleidoscope's magic legacy and understood the Second Magic's potential. The existence of an Illya with a different personality seemed perfectly plausible. "She's remarkably polite," Rin mused. "She's nothing like the Illya we have here. But Magical Girl stuff? Are you serious?"
If female magi in that world were called Magical Girls, Rin couldn't imagine herself as one. She quickly banished the terrifying possibility from her mind. At my age, why would I act like a childish girl? Magical Girl Rin Tohsaka? Utterly impossible.
"You don't know about Magical Girls?"
Although the term "Magical Girl" was coined by some lecherous old man for his own amusement, it was essentially just a Mystic Code. Magical Illya should have accepted the title long ago, Jiang You mused, guessing the reason: "Looks like this is Illya before the main story begins."
Magical Illya curiously surveyed her surroundings. She quickly spotted Shirou Emiya lying on the ground.
"Brother!"
Anxious, she tried to rush to his side to check on him, but the Duel's rules prevented her from straying too far from her Battle Zone. Only then did she notice that almost everyone around her was dressed in bizarre costumes, and some even carried weapons that gleamed with metallic light—clearly not mere props.
Coupled with the surgical scar still visible on Shirou's chest, Magical Illya's little mind had already concocted a hundred-thousand-word drama. Her legs began to tremble. "Are you... kidnappers?! If you want ransom, Illya alone will do. Please... let my brother go..."
"You might want to check what's going on in your head first," Jiang You sighed.
Illya tapped her head, feeling foolish for being so naive.
"Jiang You's Noble Phantasm should have crammed knowledge into your brain. If you'd paid any attention, you wouldn't be asking such a question. Besides, I don't even acknowledge that guy as family! And even if we're going by seniority, I should be the older sister!"
Illya was clearly particular about her family status.
"Huh?"
Magical Illya tilted her head in confusion. In her mind, Shirou Emiya, already a high schooler, was much older than her—a perfect fit for an older brother. She also wondered why the person behind her was answering from her perspective.
Then Magical Illya saw another Illya who looked exactly like her, and her brain froze momentarily.
"I get it! This is a dream!"
Magical Illya quickly convinced herself.
"Maybe we should just drop this topic?" Illya suggested. She felt there was no need to dwell on it. This innocent version of herself would be better off returning to her own world.
"Entering Battle Phase!"
"If you run into any trouble, try asking me for help. I'll definitely come to your aid."
Jiang You knew his end was near. Illya (Old Man of the Mountain) had sealed the card effects in his graveyard, and his sole backrow card was rendered useless. Desperate, he shouted at Magical Illya, hoping to trigger a new dungeon instance, similar to how Illya had served as the key to the Fifth Holy Grail War—if Konami had programmed such a mechanic.
After all, magical girls were simply too enticing. Or rather, the ability to fuse with his opponent's cards was irresistibly tempting.
"Huh?"
Magical Illya had no idea how to respond to such a sudden, nonsensical statement. She scrutinized Jiang You, wondering why he had appeared in her dream. The presence of other characters like Sakura Matou, her brother Shirou Emiya, and even herself could be traced to established connections. But Jiang You, Minamoto no Raikou, and Medusa? Their presence defied explanation.
"Um... why? And who exactly are you?"
Seeing Jiang You shamelessly trying to flirt with an alternate-world version of herself right in front of her, Illya flew into a rage. "You bastard! I'm going to beat you to a pulp today! Illya (Old Man of the Mountain), direct attack on Jiang You!"
In a Shadow Game, 4000 Attack Power was enough to shatter a person's soul.
"His name is Jiang You, right?" Magical Illya wondered. She felt a faint sense of gratitude toward him for his earlier help. Even without that, physically harming someone was simply beyond her capabilities.
"Attacking... I think I'll pass. Illya, I— Eek?!"
But in a Duel, a servant in the Battle Zone couldn't disobey their Master's command. Magical Illya watched in horror as flames engulfed her body, propelling her toward Jiang You in a way she couldn't comprehend.
"Dodge! Get out of the way!"
She had no idea where she found the strength to swing the massive greatsword. The blade crackled with ghostly blue flames as it slashed from the left side of Jiang You's neck down to his right hip, leaving a wound that could have split him in two. Eerie blue flames raged fiercely within the gaping slash.
"Waaaaaahhhhhh!"
Magical Illya screamed even before Jiang You could.
Jiang You's Life Points: 1050 → 0!
Illya wins!
"I'm sorry! I'm so sorry! I'm so sorry!"
The sickening sensation of cleaving through flesh left Magical Illya's face deathly pale with terror.
As the Duel concluded, Magical Illya's existence began to fade. Sobbing and apologizing, she vanished with the dissolution of the Duel Space, returning to her own world.