The classroom Roxy had claimed for lessons was a quiet room at the back of the Greyrat estate, filled with musty scrolls and the faint scent of ink and parchment. Sunlight filtered through the window, catching motes of dust in the air.
Rudeus was buried in a thick tome, his brow furrowed, lips moving silently as he parsed the runes.
Across the room, in a chair that he'd tilted dangerously far back, Sans balanced a cup on his head and stared at the ceiling, his expression unreadable.
Roxy had tolerated his presence during lessons at first. He never interrupted, never asked questions. He barely moved. But something about his stillness began to itch at her instincts.
He wasn't bored.
He was watching.
And more than once, he'd muttered something, quiet, sarcastic, tossed off like a joke, that contained alarming accuracy.
Today, she decided to push.
"Sans" she said without looking up from her scroll, "do you know the incantation for a Class 3 wind barrier?"
Sans didn't blink.
"sure" he said. "but i'm more of a 'let the wind do its thing' kinda guy."
Roxy looked up sharply. "That wasn't a yes or no question."
Sans smirked. "that's the trick. it's both."
She narrowed her eyes.
"You've never studied formally, you don't practice, and yet you sit here with the confidence of a seasoned adventurer."
"hey" he said, shrugging, "i'm just a naturally gifted underachiever."
Rudeus stifled a laugh, but Roxy was no longer amused.
She rose from her chair and walked toward him, robes swishing.
"Cast it,]" she said.
"what?"
"The wind barrier. Cast it. No chant."
Sans tilted his head. "what if i blow out the windows?"
"You won't."
"but what if i do?"
Roxy folded her arms. "Then you can explain to Paul why he's sleeping in a barn tonight."
The room fell silent.
For a moment, Sans didn't move.
Then, with a slow exhale, he lowered the chair onto all fours.
He didn't chant.
Didn't raise a hand.
Didn't even stand up.
And yet...
The air in the room shifted.
Subtle. Precise.
A shimmer passed through the room like ripples over glass. Papers fluttered slightly. Dust froze midair.
Then it was gone.
No sound. No flash.
Just a perfectly-formed Wind Barrier, surrounding the table where Rudeus sat, as delicate and flawless as if a master mage had spent five minutes weaving it.
Roxy stared, heart pounding.
That was... elegant. Efficient. Clean.
She stepped forward, touching the air around Rudeus. The spell shimmered under her fingers, humming with stability.
"Impossible," she murmured. "You shouldn't-"
Sans stood, cracking his neck.
"cool party trick, huh?"
She turned slowly to him.
"That's not something you stumble into, Sans. That's advanced-level theory. Where did you learn it?"
Sans just shrugged.
"guess it just came to me."
Her gaze sharpened. "That's not an answer."
"neither is this conversation" he said with a wink, turning for the door. "later, teach."
He slipped out with the ease of someone used to vanishing at the perfect moment.
Roxy stood frozen, hands clenched.
That spell... it wasn't just advanced.
It was perfect.
Outside, later that night...
Rudeus sat beside Sans beneath the stars again, chewing on a cold biscuit and trying not to ask questions.
But he couldn't help it.
"Why don't you want people to know?" he asked softly.
Sans didn't look at him.
" 'cause once they know you can do stuff, they start expectin' you to do stuff. and expectations... lead to mistakes."
Rudeus frowned. "That's kind of... depressing."
Sans shrugged. "eh. maybe. but this way, i get to sleep in."
He turned, smiled.
"besides. i already did the 'try hard, save the world' thing once. didn't work out."
Rudeus blinked. "...What?"
"nothing" Sans said quickly. "eat your biscuit, bro."
...
Roxy's suspicion keep on growing while Sans trying to avoid direct conversation with her, this keep on happening a few days later.
So about today, the three actually going for a walk around the area of the house, to the forest actually, for learning purpose.
The forest near the Greyrat estate was quiet. Too quiet.
Birds had stopped singing.
Even the wind held its breath.
Roxy stood just ahead of Rudeus, staff in hand, her brow creased. The trees had thinned, and a low mist hugged the ground like spilled smoke.
"We should turn back" she said cautiously, eyes scanning the shadows. "Something's wrong here."
Rudeus frowned. "But the mana surge...I felt it. Something's out here."
Behind them, Sans trailed with hands in his pockets, chewing on a dry twig. He hadn't cracked a joke in ten minutes.
That alone was a red flag.
They stepped into a clearing, and found it.
A beast loomed at the center. Not a creature from this world. Tall. Insectoid. Its black, glassy hide shimmered like oil in sunlight, and long arms dragged against the ground like blades.
Runes glowed faintly beneath its exoskeleton, summoning marks, but crude, unstable.
Roxy's blood turned to ice.
'That's not native to this continent.'
It turned.
And charged.
Roxy shouted, "Rudeus, back!"
She threw a barrier spell, but the creature slashed through it like paper, leaping at Rudeus before he could react.
"Rudeus-!"
He raised his arms, too slow.
But the blow never landed.
A loud CLACK echoed.
Bones.
A wall of gleaming white bones had erupted from the ground between Rudeus and the beast, shaped like ribs curving upward in a protective cage.
The monster slammed into them with a screech, stunned.
Rudeus stared.
"...What the-?"
The bones were humming.
Glowing faint blue.
And at the edge of the clearing, Sans had moved.
He stood still, left eye flickering with a bright, unnatural cyan flame, jacket fluttering in a wind that didn't exist. The air around him twisted, folded in on itself like reality was struggling to contain him.
No smile.
No slouch.
Just cold silence.
Roxy turned, stunned. "Sans..... what are you....?"
"don't move" Sans said. "i've got this."
He snapped his fingers.
The ground fractured.
Bones erupted in every direction, piercing, spinning, forming a spiral of death that surrounded the monster, boxing it in midair.
Blue strings of magic, like glowing threads, lashed out and yanked it off the ground, holding it suspended.
The creature screeched and thrashed, but couldn't move.
Rudeus whispered, "Gravity magic?"
"No" Roxy breathed, heart pounding. "That's... something else."
Sans raised his hand. Time slowed.
The monster tried to teleport.
It couldn't.
The glowing strings around it tightened. The creature shuddered once, then...
CRACK.
It imploded.
Not exploded, imploded, like it had been erased from the inside out.
Silence.
The bones vanished. The magic faded.
Sans stood quietly, eye slowly dimming, and let out a long breath.
Then he turned around.
"...yo."
Rudeus blinked, stunned. "What was that?"
Sans rubbed the back of his head. "heh... long story."
Roxy stepped forward, staff trembling in her grip.
"Those were... bones. You conjured bones, you manipulated gravity, and you....Sans, that was some kind of spatial warping magic! That's not human magic!"
Sans shrugged. "well, i'm a special kinda human, a skelly guy too right?"
"Where did you learn that? What was that energy? That wasn't man-"
He held up a hand.
"look, Rox.... i like you. but you don't wanna pull that thread."
Rudeus stepped closer. "Sans... are you really my brother?"
Sans paused.
He looked at Rudeus.
Not with a smirk.
Not with sarcasm.
Just... quiet sadness.
"....i am now."
Then he turned, bones crunching softly underfoot, and walked back toward the estate.
Neither Roxy nor Rudeus followed right away.
Because the place where that creature had been?
Was now a perfectly smooth crater.
As if it had never existed at all.
...
They didn't talk about it.
Not that day. Not the next. Not for the rest of the week.
Roxy buried herself in lesson plans, growing more meticulous and measured than ever before. She corrected Rudeus with just a bit more sharpness in her tone, watched his spell formation like a hawk, and absolutely, definitely avoided eye contact with Sans whenever he passed by.
Rudeus tried once, at dinner, to bring it up.
But Sans just gave him a look. Not angry. Not scared.
Just tired.
Like he'd already had that conversation in another lifetime, and it hadn't gone well.
So they dropped it.
Life went on.
"Alright, Rudy, again, from the top!" Roxy called, standing under the midday sun as Rudeus shaped water from the nearby river into spirals.
He nodded, hands raised, his concentration unwavering.
From under the tree nearby, Sans lounged with a straw in his mouth, hat pulled down over his eyes.
He still watched everything.
Rudeus could feel it, somehow, like the weight of a presence that wasn't really watching with eyes. Every so often, when his incantation slipped, he'd hear a quiet:
"... yo, twist your wrist left. unless you wanna drown the garden again."
And sure enough, adjusting as Sans said made the spell more stable.
Roxy noticed, of course. But she said nothing. Not anymore.
She'd once been eager to test the limits of magic, eager to challenge herself with mysteries of the arcane.
Now? She was holding back.
Because every time she thought about the way that thing had imploded..... she felt a bit less like a scholar and a bit more like a child playing with fire in a house made of dry paper.
Later that night, after supper, Rudeus sat beside Sans on the roof of the house. The stars stretched endlessly above them.
"You're still not gonna tell me where you're really from?" Rudeus asked, quietly.
Sans shrugged. "does it matter?"
Rudeus looked down at his hands. "I guess not. But... it was cool. What you did. Thanks for saving me."
Sans let out a soft sigh and looked up at the stars, eyes half-lidded.
"don't thank me yet, kid. might've just brought bigger trouble."
Rudeus tilted his head. "You mean that creature?"
Sans was quiet for a while.
Then: ".... nah. mean me."
He ruffled Rudeus' hair and gave a small smile.
"get some sleep, short stuff. tomorrow, you're gonna nail that water spiral. bet on it."
"...You're watching over me, huh?"
"nah," Sans said, eyes closing. "i'm just here to catch the parts you drop."
And just like that, they went back to pretending things were normal.
But beneath the surface of the quiet Greyrat estate, a hidden power slumbered, wrapped in laziness and smiles.
And deep down, they all knew....
It wouldn't stay asleep forever.
...
The following day...
"Alright, Rudy," Roxy said, tapping her staff against the grass. "Concentrate this time. I want to see you maintain the water globe without losing shape or temperature. Got it?"
"Yup!" Rudeus said with suspicious enthusiasm. A little too enthusiastic, actually.
He stood in front of her with both hands raised, carefully forming a floating orb of crystal-clear water. His gaze, however, was not entirely focused on the spell.
It drifted.
South.
'Just a quick peek' he thought. 'It's educational.'
Roxy, unaware, leaned forward slightly, observing the orb's subtle tremble.
And then—SPLASH.
The orb collapsed, soaking his face and shirt.
From the shade of a nearby tree, a lazy voice called out: "wow. impressive. it took you a whole eight seconds this time before the hormone hurricane kicked in."
Rudeus sputtered and spun. "Sans!"
Sans was reclined against the tree trunk, hands behind his head, one eye half-lidded, the other glowing ever so faintly.
"look, kid," Sans said, standing up and strolling over, "i get it. she's cute. she's blue. she's got that whole mysterious-mage vibe. but you gotta tone it down."
He leaned closer, voice flat.
"you're not slick. i can literally feel secondhand embarrassment leaking off you like a bad smell."
Roxy blinked. "What's going on?"
Rudeus coughed. "N-nothing! Just a minor lapse in focus!"
Sans gave her a thumbs-up. "don't worry, rox. he's just admiring the.... spellcasting form."
Roxy nodded. "Oh, I see. That's.... wait a minute."
She turned around. "Rudeus."
"Yes, ma'am!"
"Eyes up here, not on my thighs."
Rudeus froze like he'd been hit with a petrify spell.
Sans leaned over and muttered, "ya know, if you keep doing that, your mana won't be the only thing getting expelled."
Later That Day
They were back in the study, books scattered, and scrolls half-unrolled. Rudeus sat at his desk, scribbling down incantation runes with furious intensity. Sans, across the room, had made himself comfortable in a hammock that he definitely didn't ask permission to hang.
Roxy walked by, setting down a cup of tea.
Rudeus' gaze followed her for just a beat too long.
Snap!
A bone, yes, a literal bone, suddenly bonked him on the back of the head.
"Sans!"
"what? reflex." Sans stretched. "you look at her like that one more time and i might accidentally teleport your eyeballs into your shoes."
Roxy raised a brow. "Teleportation magic?"
Sans grinned. "eh, it's experimental. but it's eye-opening."
Rudeus groaned and slumped onto the desk. "I'm never gonna get a girlfriend if you keep cockblocking me."
Sans clapped a hand on his shoulder, voice grave.
"kid... if your game starts with 'hi i'm ten and i cast fireballs~' then you were never in the match to begin with."
Evening
Dinner was quiet, as usual. Zenith fussed over the food, Paul was already tipsy, and Roxy had retreated to her room early to avoid... certain gazes.
Sans poked his food with a fork, lazily chewing while watching Rudeus fiddle with a spoon in silence.
Then, softly:
"...you're gonna scare her off if you don't chill, you know."
Rudeus looked up, ears red. "I'm just... curious."
Sans tilted his head. "curious is when you read a book. not when you ogle your magic teacher like she's dessert."
He paused. "unless you are into that kind of spellcasting. which, in that case, i'm callin' the feds."
"...What are feds?"
"you don't wanna know."
And so the days passed, lessons, spells, awkwardness, and Sans looming like the laziest watchdog ever born.
He never said no to helping Rudy grow.
But when that growth took the wrong direction?
He was right there with the bone jokes and guilt trips.
And somehow... that made all the difference
.
.
.
.
Not that much actually.