Roswaal was a student of Beatrice's mother—the Witch of Greed, Echidna.
Because this man had been born with an overwhelming talent for magic, he was plagued by the Mana Release Period, and so was often misunderstood by those around him. Not until he met Echidna.
As Echidna's student, he'd shared plenty of good times with her daughter Beatrice too. Once, Beatrice trapped some child in a walk-in-circles prank; to help the kid get even, the very next day Roswaal turned the same looping trick on Beatrice.
Back then Beatrice hadn't much wanted to admit it, but looking back now, that probably counted as friendship as well.
Over the centuries, Beatrice had watched several generations of Roswaal come to the Forbidden Library for books. Some of them men, some women, and all along it had been the very same person she knew so well.
She'd thought she would never see her old friend from those days again, yet in truth this man had been right under her nose the whole time.
Still, she understood why Roswaal had never come clean with her. After all, prolonging one's own life through one's direct descendants was far too immoral a thing.
So—
"Bring your face a little closer."
Beatrice turned Yimi away, slipped off one of her little leather shoes, took it in hand, and stamped it hard across Roswaal's face, leaving a mark.
"Beatrice-sama..."
Roswaal cupped his cheek. "Does that settle your anger, then?"
"You're thinking too simply, Diego." Beatrice answered coldly. "I merely didn't want to show this child my more violent side."
Roswaal blinked, then let out a small laugh. "I see. So she's the one you've decided on—your 'That Person'? Not even Ryuzu was ever shown such open tenderness by you~, was she."
Beatrice narrowed her eyes. "If that child knew what you've turned into, I wonder what she'd think."
"So you finally admit it. All this time you've been a stone weighing on my chest. I'd already dealt with several Sin Archbishops, and yet I couldn't sleep easy."
Natsuki Subaru cracked his knuckles, glaring at him. "Now, while Ram and the others are still willing to cover for you, you've still got a chance to explain yourself properly, Diego."
"I keep telling you—Diego is not, a good guy. You don't believe me." Yimi turned around, a note of grievance in her words.
So what on earth was Diego, anyway?
"Heh heh, Subaru-san, it seems you still haven't reached the level that would satisfy me~." Roswaal gave another helpless little smile.
To go to any length for the one he loved, to bring his teacher back and return to a life like the old days—that had been his single cherished wish for a hundred years.
Everything, all of it, had followed the guidance of the Book of Wisdom: whether abandoning the maids to head for the Sanctuary just before disaster struck, or passing the Book of Wisdom's information to the Sin Archbishops so that danger would be summoned down on Natsuki Subaru and the rest.
"But now that you've come all the way here, what you ought to be thinking about isn't what I want to do~. As you can see, I'm nothing but a harmless wounded man." Roswaal waved a bandage-wrapped arm.
"'Never mind what you've done'... what's that supposed to mean?"
Natsuki Subaru's confusion made Roswaal glance at Beatrice, a little surprised. "So you came all the way here without telling them anything?"
Beatrice frowned faintly. On the road her mind had been full of Yimi's talk about leaving this world, and she'd completely forgotten to explain the details of the Sanctuary.
Roswaal turned a meaningful look on Emilia, the half-elf. "Emilia-sama is trapped here~, you see."
"Eh?"
"That's how it is. Rather than bothering a wounded man like me, you'd all do better to go and work out how to pass the Sanctuary's Trial. If there's anything you don't understand, any of the residents here can clear it up for you~. Now then, might you leave for a while and let this poor invalid rest?"
Roswaal raised both hands—and never expected that the little cat he'd been watching most closely would suddenly produce her Spear.
"I want, to finish him off!"
Why leave now? Diego was already hurt. If she didn't pin him down and study him properly while she had the chance, when else?
"Wait, Yimi-sama!" Ram hurried to block the way in front of Roswaal, the single horn Yimi had healed manifesting straight out of her forehead.
"Please leave this to me for now."
"Ram, you—?" Roswaal stared, startled at the horn on her brow.
Ram turned to face him. "Yimi-sama stuck it back on for me with her saliva."
"..."
In the tense air, Roswaal decided to set aside, for the moment, that deeply unsettling method of repair, and smiled. "I see. Ram, with your horn restored, you're now qualified to take your revenge on me. A mere ordinary release of mana from you already verges on grand magic."
A prodigy who, even as a child, could throw herself into a crowd of Witch Cultists and cut them down. Grown, her strength would naturally rank among the world's top ten.
When the Oni were attacked by the Witch Cult, he had in fact known of it in advance through the Book of Wisdom. But, as the Book dictated, he had not intervened, and had simply taken Rem and Ram in.
From Ram's standpoint, hating him for his deliberate inaction was perfectly understandable.
"It must be painful for you, having to cling to a man you despise just to keep living?"
"Regrettably, you've guessed wrong, Roswaal-sama. Ram has never once resented you." For the first time since her oni horn was restored, she let her power show.
On the contrary—what she was doing now was protecting Roswaal from Yimi's hands.
She meant to destroy the Book of Wisdom, the thing that had driven Roswaal to every one of these acts.
"But releasing mana here without restraint really is most unwise, Ram." Roswaal gazed into the distance.
Before the group had come running to the Sanctuary to find him, he had already turned the pages of the Book of Wisdom once more. Though, being a mere replica, it never told him plainly everything that would come to pass, there was one phrase he remembered very clearly.
The 'Great Rabbit'—famed alongside the White Whale as one of the Three Great Mabeasts. Or, to be precise, the 'Many-Rabbit.'
Its true form was a rabbit no bigger than a human palm, but it was a terror that split without end and gnawed everything in its path. As long as a single one lived, it could never be wiped out clean, and it was drawn to large quantities of mana.
Roswaal rose from his sickbed and looked at the wary Natsuki Subaru. "Do try not to be so reckless 'next time,' Subaru-san~."
"Watch closely."
Inside the dragon-carriage cabin, at the direction of Otto—who hadn't left—the bug before them suddenly did a backflip.
Meili, enjoying the performance, clapped at once. "So gross!"
"Shouldn't a normal kid say 'amazing' instead?" Otto took the hit hard.
He possessed the Divine Protection of the Soul of Language; its effect let him understand the voices of anything that could make sound, and he used it mostly to control insects. They were everywhere, and could be bought off with nothing more than sugar water.
Once, he'd been dragged into some noble daughter's love affair and saddled with a trumped-up crime. To clear his name he'd used his ability to gather evidence far and wide, and learned that the woman had slept with eight different men. So he'd charged over and said as much, right in front of the woman and her boyfriend...
And after that he'd left his home behind and taken up the merchant's trade.
"I keep getting the feeling Meili's deliberately avoiding that cat-eared kid," Otto asked, as though in passing. "Is it because of the legend about the man-eating catgirl?"
They were the only two who hadn't gotten off. He'd wanted to talk to the Margrave about goods, but that little hut couldn't fit this many people.
Otto scratched his head, embarrassed. "It's a bit funny, actually—the merchant who supposedly got eaten in that legend was me."
"Hm? Did someone say something like that? Don't tell me Mister Cuckold is one of those 'thinks-highly-of-himself' types. Is there some unspeakable secret behind you getting close to little Meili, too?"
Meili clutched her chest and scooted a little farther from him.
"It's not like that! And here I thought I could play the part of a caring big brother and talk you through things—you looked so down earlier—turns out you're a scheming little thing after all..."
"But that kid really isn't so scary, is she? Thanks to her, we merchants even gained a safe new trade route out of it."
"That's not the reason." Meili sat at the edge of the cabin, swinging the little legs that couldn't reach the floor.
While Yimi was comforting her, the little runt could never have guessed that Meili had been ready to strangle her only moments before. That was why, whenever she saw the runt's face, Meili couldn't help but look away.
What was she thinking now, anyway? Whether she still wanted to strangle that kid—even she couldn't quite tell anymore. The 'mother' who'd been her greatest fear was already dead...
Still, thinking this way, her imitation of Elsa really wasn't up to par, was it.
"Hm?" As if he'd heard something, Otto turned warily toward the distant woods.
As though sensing some threat, every crawling insect let out a sound that split his skull: fear and lament. Something dreadful was coming.
In the forest, dense eyes glinted with a soul-snatching light, closing in from every angle, leaving nowhere at all to flee.
"What's going on, Mister Cuckold?"
Meili, who felt the wrongness too, shot to her feet, following the lamp Otto had raised toward the horror that had, in an instant, drawn near.
One of the Three Great Mabeasts—the Great Rabbit.
At the sight of its true form, Meili's pupils shrank a fraction; she almost screamed the way an ordinary little girl would, a scream she'd never once made in her whole life.
Countless frogs, cheeks puffing, came leaping toward them—because when Yimi had transferred Meili's misfortune away that day, it had landed squarely on their heads.
Roswaal, who a moment ago had held everything in the palm of his hand, felt his expression stiffen slightly.
This was the Great Rabbit?
Congratulations, Host—achievement unlocked: [Spring BOSS]. Reward: +5% Portal Energy.