Hello and welcome to my first-ever Honkai: Star Rail fanfic featuring our favorite Landau siblings!

Now some context for those unfamiliar, this story takes place after the final battle at Everwinter Hill. I've taken some creative liberties here to get these two in this situation, but that's about it. Enjoy!

And wincest, to boot! So if you're into that, hope you guys have a great time!

Now, this is one of the Side Stories that I have for my highest tier of patrons. So unlike the Summer Chateau and the Conquest of Menagerie, this one isn't gong to be getting updated, at least publicly, after the first chapter.

So if you're interested in seeing the second chapter - and any others that'll follow - you can find them on my ℙ𝕒𝕥𝕣𝕖𝕠𝕟 account:

𝕡𝕒𝕥𝕣𝕖𝕠𝕟.𝕔𝕠𝕞/𝕋𝕠𝕡𝕙𝕥𝕙𝕖𝕋𝕣𝕚𝕔𝕜𝕤𝕥𝕖𝕣

Chapter 1

The last thing he'd remembered were axe blades of fire and ice, blasts that pushed him back even as he held the line. Cries of fear and panic as artillery thundered around him.

It might have been the most glorious moment of his life. Here he was, Commander Landau holding the line against the Fragmentum as the Engine of Creation stood for the first time in seven hundred years to face the source of their world's slow descent into decay.

He was the shield of Belobog, and he'd protect it while the final battle was fought.

And then the light came down from heaven. Pain, shouts, screams, and an upwelling of terrible rage. He had vague memories of what followed, his hands thrashing about as the fragmentum threatened to overrun them.

By the time he'd finished with them, everything had gone dark.

The last thing he'd remembered before the world turned cold had been the sound of his sister's voice.

~TtT~

When he woke, it was to the familiar amber light of his room, and the soft comfort of his bed.

It was sunset. Sunset when he knew it took hours to get back to the city from the frontline, and the fighting had started in the afternoon. It would have been late-night by the time he'd have come back.

He'd been out for at least a day.

Preservation! The battle! The Stellaron!

Gepard started as he tried to get up. He'd been the commanding officer that day. His men!

His sister!

The pain that followed was swift and without mercy. Arms gave way and it hurt enough that he'd involuntarily thrashed about his bed. The rest of him followed, seething pain running up and down the entirety of him. He was blinded by it, crying out.

"Gepard!"

Cool hands held him down by the shoulders, fighting against the spasms. He felt the light brush of her hair against his face. Gritting his teeth, Gepard tried to center himself. Fight the pain with discipline. Fight the pain because he'd fought it before. He'd won.

He did again.

Her hands were callused. They'd been for years now. It was a testament to her hard work as both an engineer and a musician. Despite that, they'd always managed to stay dainty somehow. Beautiful. And he'd lost count of how much her touch had comforted him over the years.

When he opened his eyes, it was to meet a mirror of his own. She was leaning over him, staring at him. Her face was framed by honey blonde hair as it fell around him in a curtain.

Gepard's mouth opened. He pulled in a breath. He tried to speak.

The breath that came out was raspy, weak. Serval frowned.

"You need water."

He drank deeply as Serval raised the glass to his lips, lifting his head so he could get more. The cold was a welcome relief from the dryness in his throat. His sister's hand came up to hold up his head as he finished the remainder of the glass.

"You're here." He asked, but not really. Leaning into her hand even as he turned towards her.

"Yeah, well you got put here because of me, so I figured I ought to keep an eye on you." Her eyes misted up, lips pursed as her now-free hand clenched atop her lap. "It was a close thing, Geppie. Doctor said you might have made it if we hadn't rushed you back after the final battle."

Her attention was elsewhere now. It was a sight familiar to him enough, though he didn't know how familiar his sister might have been with it.

Serval's hand was warm against his cheek, though it rubbed against him absentmindedly. He gave it a nuzzle, put his lips against her palm and hummed into it. She started.

"I'm here, sister." His voice was low even by his standards, gruff, almost gravelly. "You got me home."

Her eyes snapped to his, blinked. "I-I… I did, didn't I? W-well, it wasn't just me. Caelus and his crew had helped get you here, and-"

She rambled. Gepard let her. His sister got like this when she was flustered. She'd talk a mile a minute sometimes about nothing at all. But this was better than being stuck in her head. He nodded, kept his cheek against her hand while sending her the occasional humm to tell her he was listening.

Turned out he was carried to the hospital by his men once reinforcements arrived. After the removal of the Stellaron, the Fragmentum attack had slowed.

Gepard could scarcely believe it. They'd won. The Everwinter was broken, and though it might take decades for the snows to finally fall away - if not longer - it wouldn't get any worse.

Finally, he leaned back as the thought of that sank in, and everything that entailed.

Again, he turned to her, reached out and grabbed her hand. "You stayed."

She was dressed in one of his shirts and a pair of threadbare joggers that looked to have come from her university days.

"Of course I stayed!" Her cheeks flushed, and she'd tried to pull her hand back from his in what might have been a flinch. Gepard held on. "No one else was going to keep an eye on you. Too much going on."

That got her started again, this time telling him about the aftermath, with Bronya ascending to the office of Supreme Guardian alongside the truth that was told to the rest of the public.

"Also, when were you going to tell me you were head of the family!?" She interjected, actually managing to snatch her arm back before slapping his shoulder with it. "This whole time you were already Lord Landau, and hadn't breathed a word of it to me!"

He immediately regretted laughing. Laughing hurt.

Serval's response was to hit him some more.

~TtT~

The week went by in a blur, mostly because he'd spent most of it asleep.

And Serval had stayed over through all of it. She'd not quite waited on him hand and foot, of course, but she'd been constant company to him, especially when the doctors had forbidden him from doing anything besides bed-rest. She'd helped him get up to use the restroom, and to wash.

She'd even put-off going to her workshop, usually just getting daily visits from her assistant in the afternoons for updates. The desk he'd kept in the master bedroom - once their father's - had been converted into Serval's makeshift office while she stayed with him. Most times he'd woken up, it was to see her bent over blueprints, filed reports, and who knew what else while dressed in something terribly comfortable.

It warmed his heart to see her back here, back in their home. And there was something about seeing her go about the house, sitting with him on the quiet afternoons that he was awake, and seamlessly sliding into the hierarchy of the household. Gepard had already caught some of the servants deferring to her on some of the daily running of the house.

"Stay." He'd told her, after a moment of weakness where she'd helped him bathe and dress before they'd settled down for dinner at his bed. "Come back to us."

Serval's eyes only twinkled as she'd finished her meal.

That night, she slept in his bed, and did so until his final check-up weeks later.

~TtT~

The bite woke him.

His first instinct was to pull away, to prepare for a fight. It was rare for this to-

"Good morning Lord Landau."

Her hot breath brushed against his neck as she whispered. Gepard could practically hear the grin on her face without having to look down, instead eying the polished wooden paneling of the ceiling above as he felt her hand brush up his legs.

"Oh does this please, my lord?" His sister's giggle rang like bells in his ears as her hand pressed down on his thigh at the twitching thrust of his hips. Sapphire eyes met his own and a stirring flame was lit at the pit of Gepard's stomach.

Soft flesh and calloused fingers - engineer's fingers - pressed against him, molded against his body.

"Good morning, Serval," His voice was choked, raspy, sleepy, but Gepard's mind was a whirr.

They were both covered by the sheets, only Serval's head and shoulder visible to him as he looked down, but he could see - could feel - that she wasn't wearing anything underneath. Further down, her hand drew circles around his upper thigh. His cock stiffened in anticipation.

His sister leaned in closer. "My lord has been cleared by the doctors yesterday. A clean bill of health." Fingers were running up to his groin now, cupped at his balls and Gepard gasped. "So I figured you could do with a pleasant morning wake-up."

She planted a kiss underneath his jaw while her hand stroked up his shaft. Pleasant shocks ran up his spine and Gepard leaned into her while wrapping her with an arm. He caught a handful of hot assflesh, one of his fingers just barely brushing where it met her thigh.

He caught the wetness there. Dripping.

"Hngg," she moaned, "Does my body please you, Lord Landau?" She'd pulled down his pants now, freeing him from its tight confines and pulling a relieved sigh from him now that his growing hardness wasn't constrained.

"It feels like it does!" Serval cooed as she cupped his head and twisted. The motion made him shiver. She followed this up with a full downstroke and then taking the extra time to give his balls a fondle before going back up. "And I'm glad you seem to be enjoying this, too."

His sister pulled away and planted another kiss on the edge of his lips. Gepard could feel the stiffness of her nipples against his bare chest. They drew his attention even though he couldn't see them, making him reach out to them with his free hand to give one of them a tweak.

Serval moaned. The hand around his cock froze and squeezed in just the most delicious way that his hips did another involuntary thrust. Her face was flush, mouth open just enough. Blue-streaked, honey-blonde hair fell around her in a light mess that made her look absolutely gorgeous.

Gepard couldn't resist. He leaned in.

The hand around his cock jerked again as their lips met. He grabbed one of her tits and pulled her closer - practically on top of him. One of Serval's thighs brushed against his ballsack and he could feel his cock twitch in her grip.

His sister groaned into his mouth, eyes closed as her tongue came to meet his.

Serval's lips were soft, plump. They molded against his the way her body did against him, and he could feel the grin she wore as his grip tightened around her.

His sister redoubled her efforts, taking her time when cupping the head to draw some of his precum unto her palm. She was gliding up and down his shaft shortly afterwards.

Gepard was the one to pull back first, leaning into his pillows as he gazed down at her. His sister's sapphire eyes were clouded, and her tongue stuck out as she moved to follow him, wanting more. He responded by giving her ass a light smack.

This time, it was her hips that jolted, thrusting against his thigh and rubbing her wet entrance on him. She moaned at the stimulation, and the hand tending to his cock ceased a moment before she continued.

"I'm supposed to be taking care of you here, Lord Landau." She whispered, her own voice low and thick with arousal. He answered with a pleased hum as he leaned in to take a deep breath of her hair. "Please let me."

Gepard didn't answer, but he nodded against the crown of her head and took his hand away from her tit to let her focus better. Despite that, he gave her ass another squeeze.

What followed was best described as worship.

Serval planted kisses on his neck, along his shoulders, his chest. Each touch placing hot marks against his skin while her other hand moved down to join the other on his cock.

Her movements became more energetic, one hand focusing on his cockhead while the other continued to tend to his shaft and balls.

"I'd been surprised when I'd learned that you'd already ascended to the position of head of the family, Gepard." She said when she'd settled on his abdomen. It allowed her a more comfortable angle to continue tending to his cock, but all it allowed him to see was her hair, electric blue peeking out from underneath the blankets.

"You'd been fighting so long." Her voice was muffled by the sheets, "You'd taken on father's responsibilities years ago, too. I hadn't even known…" Then her hair faded into the black.

And he felt her lips wrap around the head of his cock, pulling a loud groan from him. Serval's tongue swirled at his glans, spit coming past her lips and going down his shaft in rivulets. Her hands caught all of it and used it to lube up her stroking.

Gepard, meanwhile, could only see the bulge of his sister's head tenting the blankets. He closed his eyes and focused on the sensation of her.

Spit-slick fingers fondled his balls, her digits alternating between each of them as though coaxing them to make more cum for him to shoot. The hand stroking his shaft twisted about as it went up and down, squeezed rhythmically while doing so. Pressure and grip varied moment to moment, each highlighted with a smooth glide, and a glorious contrast between soft and calloused touches.

All crowned by the gentle suckling of her lips while she hummed a lullaby into his cock.

When she pulled up, it was with the sound of a pop and the hand on his balls immediately moving to his head to make up the difference.

"I almost lost you, Lord Landau," she said, "I was scared out of my mind when the Fragmentum caught you." Her tongue licked at his slit, copious amounts of spit coating his spongy head as her hands spread it down his shaft and cupped his balls again. She squeezed.

She pulled away with a giggle when his hips thrust his cock up. Gepard couldn't resist a smile even as he shivered from the stimulation.

"You've been doing so much for so long, Geppie." He felt her plant a kiss on his pelvis while her hands continued their glorious work. Preservation, that made him stiffer than the sucking. "Like that, little brother?" She kissed him again, and again his cock twitched in her hands. Serval giggled.

"Hmm…" A finger - a thumb, maybe - rubbed over his slit as her stroking on his cock slowed. This time both hands joined in though, going up and down with fingers joining in for featherlight brushes. It would have tickled if he hadn't found it so arousing. "I'm glad you made it." She whispered, planting another kiss, "I'd have missed you terribly."

There was a shift, the bulge where her head was moving slower while her hands twisted about his cock in a slowly tightening grip. A hot, wet, slimy grip.

"I love you, Lord Gepard Landau."

And then she took his balls into her mouth. Her hands also picked up the pace again, one stroking his shaft while the other stimulated his cockhead.

"Sister!" He hissed behind grit teeth, hips stopped from thrusting only thanks to Serval straddling his legs. Despite the stimulation, though, Gepard caught it, the way her dripping pussy rubbed against one of his shins. But that was eventually overtaken by the tightening of his crotch, the churning of his balls, and his hips beginning to thrust upwards into her heavenly hands.

With a groan, the first spurt of cum shot out into her warm and wet hand. The mouth around his balls immediately pulled away with another pop before his cock wrapped around the furnace between his sister's lips.

Still, she stroked him, more gently now and always with a tighter grip as she moved towards the head. She was milking him into her mouth, pulling out every drop of cum. He could even feel her sucking at his slit, drawing more of his essence from him while her tongue continued its work.

When he'd finished, when he was starting to soften in her grip while she still kept going, the blanket was pulled back. Their eyes met, hers filled with both warmth and satisfaction. Gepard was sure his was more filled with exhaustion, nevermind that she'd been the one doing all the work.

Then she pulled away and opened her mouth. He saw a pool of himself there, so thick he couldn't see the bottom of her mouth, and her tongue stuck out of it like the fins or some shark. She swirled it about her mouth then raised the hand that had caught the first shot of his load.

Slowly, ever so slowly, she tripped the semen into her mouth, all without breaking eye contact with him.

When there was too little left, she licked it up before showing him his load one more time.

A gulp later, it was gone, Serval leaning forward and sticking her tongue out to show him her clean mouth. It took only a beat of her looking at the expression on his face for her to break out into a fit of giggles.

"Oh you definitely liked that." She bent down to plant another kiss on his crotch, and she got hit by his twitching hardness for her troubles. She cooed at the sight of his revitalized cock. "Liked it enough to want a second round, even."

Sapphire eyes shone, and Preservation did she look hot with his shaft brushing against her cheek and just a bit of his cum dripping down her chin.

"Well, I know you have the whole day free today." Her voice had that lilt of mischief that reminded him of their childhood, when they would both sneak out for a fun day outside. Except this time, there was an undercurrent to it that stoked a fire inside him. "I think I can service Lord Landau a little more."

She shifted, shimmying herself up his body in a half-crawl until her dripping lips hovered just above his cockhead. He could feel it each time her arousal fell upon him, hot and wet, while her hands pawed at his torso.

Her touch lingered on scars, many he'd earned in the years since he'd started serving, a few more newer ones from his recent run-in with death.

"Would my dear lord want that?" Serval whispered into his ear after she leaned down and wrapped his head up in her arms. An embrace that was a cross between affectionate and enticing all at once. She buried her face into his shoulder while he was surrounded by her blue and gold locks, the smell of her filling him. All the while, she rocked her hips back and forth, teasing him with her entrance.

"From dawn to dusk, sister."

I'd love to hear what you guys think of the story so far. Thanks for taking the time to read!

For those interested in seeing the second chapter (which just went up as of the time of posting), you can do so on my ℙ𝕒𝕥𝕣𝕖𝕠𝕟:
𝕡𝕒𝕥𝕣𝕖𝕠𝕟.𝕔𝕠𝕞/𝕋𝕠𝕡𝕙𝕥𝕙𝕖𝕋𝕣𝕚𝕔𝕜𝕤𝕥𝕖𝕣

And in case you'd like to see updates my writing updates such as when I get started on a chapter or when stuff gets posted up on my twitter:

𝕙𝕥𝕥𝕡𝕤:/𝕥𝕨𝕚𝕥𝕥𝕖𝕣.𝕔𝕠𝕞/𝕋𝕠𝕡𝕙𝕋𝕣𝕚𝕔𝕜𝕤𝕥𝕖𝕣