Sitonai—originally referring to the young heroine of Ainu mythology—could, in the world of Type-Moon, also denote a certain composite Heroic Spirit.
In Fate/Grand Order, the Servant known as Sitonai is born from Illya as the core, fused with the Ainu mythological Sitonai, the Finnish mythological Louhi, and the Norse mythological Freyja. Though the name is "Sitonai," it is actually an amalgamation of four entities. Since Sitonai's outward traits are the most prominent, the name was adopted.
Of course, while called Sitonai, Illya's consciousness remains the dominant force—essentially, a human mind piloting a Servant's body.
Zuke had considered many possibilities, but he never expected that Illya wouldn't just summon some strange Servant—instead, she had become the special Servant Sitonai herself.
It seemed the reason Illya slaughtered everyone in the Einzbern castle was due to the lingering influence of Louhi, the witch whose spirit had been fused into her.
The Einzberns' desperate, almost reckless measures had actually succeeded in manifesting a Servant like Sitonai—unfortunately for them, they failed to control her.
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"You will not threaten Illya!"
While Zuke was pondering the details about Sitonai, the two maids, Sella and Leysritt, continued their relentless assault on him.
Yet, with each successive attack, their hearts sank further—because no matter what they tried, Zuke didn't even bother moving.
He simply stood there, tanking everything they threw at him. Whether it was sharp strikes, magical threads, or the edge of a massive axe—everything was shrugged off effortlessly.
And throughout it all, Zuke's expression didn't change in the slightest. Forget leaving a scratch—they hadn't even managed to break a single strand of his hair!
Still, the two maids fought on, loyal to their duty of protecting Illya.
"Your devotion is admirable, but even I'll get annoyed if you keep attacking me~."
Just as Sella and Leysritt prepared for another assault, Zuke finally made his move.
Given that their attacks were motivated by their desire to protect Illya, he hadn't felt the need to retaliate—but it seemed the two still hadn't grasped the reality of the situation.
Persisting despite knowing it's futile is a commendable trait from a master's perspective, but from an enemy's standpoint? Annoying.
And unfortunately for them, Zuke was currently the "enemy." It was time to cool their heads.
In the next instant, Zuke appeared right in front of the two maids. His hands shot out, clamping around their necks before slamming them both against the wall.
"Gh—!"
A stifled gasp escaped them as their backs hit the hard surface. Even then, they struggled—but Zuke's grip, light as it seemed, sapped all strength from their bodies.
Just as he was about to speak—
Boom!
A surge of frigid air exploded from behind him.
Zuke blinked, turning his head to see the bedroom door blasted open—and standing there, glaring coldly at him, was Illya.
Or rather, Sitonai—though Illya's consciousness was dominant, given the fusion of multiple Heroic and Divine Spirits, "Sitonai" was the more accurate term.
"Let go of Sella and Leysritt!"
Her voice was sharp as an icy gale erupted from her body. A bone-chilling cold instantly seeped into Zuke's flesh—enough to freeze an ordinary person solid in seconds.
This was Sitonai's inherent skill, Snow Fairy—the ability to freeze anything at will.
But Zuke's ki flared, forming an invisible barrier that halted the invasive cold before it could penetrate deeper.
"Finally came out, huh? Seems you do care about your maids after all."
With a chuckle, he released his grip, letting Sella and Leysritt drop to the floor.
"Cough—! ...Terrifying."
The moment she was free, Sella coughed violently, forcing her voice to work as she shouted toward Sitonai.
"Illya! Run! This guy is strong! Even you—!"
Though Illya, as Sitonai, had displayed monstrous power back in the Einzbern castle, Sella could tell—Zuke was on another level entirely.
Against the Einzberns' resistance, Sitonai had needed to evade or defend with her ice. But Zuke? He hadn't even flinched under the same attacks.
That alone spoke volumes about the gap between them.
Yet Sitonai showed no intention of fleeing. Instead, she kept her gaze locked onto Zuke, her stance firm—ready to fight.
"Looks like I'll have to discipline you first before we can talk properly, huh?"
Zuke grinned.
The Sitonai from FGO hadn't been this fierce.
But then again, that version of Illya had already reached the end of her story, her emotions stabilized.
The Illya before him now? She had lost her mother, suffered cruelty at her family's hands, and was drowning in distrust for the world.
So while both were "Sitonai," their behaviors were worlds apart.
Not that it mattered to Zuke—if Sitonai wouldn't listen, he'd just have to make her listen.
"Teaching your daughter a lesson is part of being a father, after all."
Cracking his knuckles, he smirked as the air around Sitonai thickened with frost.
Time to discipline his unruly "daughter."
In the slice-of-life world, Illya had been well-behaved, so he'd never had the chance.
But here, in the Fate/Stay Night mission world?
Oh, he was going to enjoy this.
To be continued…