Chapter 1: Introduction
The air in the dimly lit basement was thick with the scent of damp earth and something else—something electric. The flickering glow of a single bulb cast long shadows across the concrete floor, where jars of strange, glowing herbs sat in neat rows. Eren’s fingers trembled as he held one up to the light, the deep green leaves pulsing faintly, as if alive.
“You sure about this?” Armin asked, his blue eyes wide behind his glasses. He was shorter than Eren, but his mind was sharper, his voice steady even as his fingers drummed nervously against the table. “We don’t even know what this thing does.”
Eren grinned, his green eyes alight with excitement.
"Come on, Armin, where's your sense of adventure? We’ve been stuck in this cycle of training and waiting for years. This could be the breakthrough we’ve been looking for."
Armin adjusted his glasses, his blonde hair falling slightly over his forehead as he leaned in to examine the herb. "Breakthrough or disaster? We don’t even know if it’s safe. What if it mutates us into something worse than Titans?"
Eren scoffed, rolling his eyes. "Since when did you get so cautious? You’re the one who suggested we test it in the first place."
Armin crossed his arms, his short stature making him look even more like a scolded child.
"I *suggested* we *research* it first. There’s a difference between curiosity and recklessness."
Eren smirked, tossing the herb between his hands like a coin. "And what’s life without a little recklessness? Besides, if this thing works the way we think it does, imagine what it could mean for us. For *her*."
A shadow passed over Armin’s face. He knew exactly who Eren meant. "You’re talking about Mikasa."
Eren’s grin didn’t waver, but his fingers tightened slightly around the herb. "Who else? She’s the strongest fighter we’ve got.
Imagine what she could do with this.” Eren’s voice was low, almost reverent, as he turned the herb over in his palm. The faint glow pulsed in time with his heartbeat, as if the plant itself was responding to his excitement.
Armin exhaled sharply, running a hand through his blonde hair. “You’re not just thinking about her strength, are you?”
Eren’s smirk faltered for just a second—just long enough for Armin to know he’d hit the mark. “What’s wrong with wanting her to be even more impressive?” Eren countered, his tone defensive. “She’s already incredible. So we only will make her even better ,” Eren said, his voice low and deliberate. He turned the glowing herb between his fingers, the faint pulse of light casting shifting shadows across his sharp features. The basement air was thick with tension, the scent of damp earth and something sharper—something alive.
They take enough herbs for Mikasa, and they head to the Training Grounds.
The Training Grounds stretched out before them, vast and open, the grass trampled from hours of relentless training. The distant shouts of soldiers echoed in the evening air, their grunts and the clash of steel blending into a rhythmic symphony of discipline. The sun hung low, casting long shadows that stretched like fingers across the field. Eren adjusted the strap of his bag, the weight of the herbs inside pressing against his side like a secret.
Armin walked beside him, his shorter frame moving with quick, precise steps. "You're sure she'll agree to this?" he asked, his voice low.
"You know how she is about Eren. If she thinks this is some kind of trick to make her even more... *attractive* to him, she might lose it."
Eren smirked, though his fingers tightened around the strap of his bag. "She won’t lose it. She’ll be *thankful*."
Armin shot him a skeptical glance. "You’re playing with fire, you know that?"
Eren didn’t answer. His eyes were already scanning the training grounds, searching for the familiar silhouette of Mikasa. She was easy to spot—even among the disciplined ranks of the Survey Corps, her presence commanded attention. Her breast are an g-cup . Mikasa stood at the edge of the obstacle course, her black hair pulled back into a tight braid, her muscles coiled like steel beneath her uniform. She moved with effortless precision, her body a weapon honed to lethal perfection. But as Eren watched her, his pulse quickened—not just from admiration, but from something deeper, something that made his throat tighten.
Armin nudged him. "You’re staring."
Eren didn’t look away. "She’s just… impressive."
Armin sighed. "You’re going to get yourself killed."
Eren grinned. "Worth it."
Mikasa turned then, her sharp eyes locking onto them instantly.
Even from a distance, Eren could see the way her gaze softened when it landed on him—just for a second, before her usual stoic expression returned. She wiped the sweat from her brow with the back of her hand, her biceps flexing in the fading sunlight. The sight made Eren’s pulse quicken.
Armin elbowed him. "Subtle," he muttered.
Eren ignored him, stepping forward as Mikasa approached. The way her boots dug into the dirt with each stride sent a thrill through him. She was always strong, but now—now there was something different about her. Something *more*.
"Eren," she said, her voice low and smooth.
The way she said his name sent a jolt through him, like a current of electricity. "What are you two doing here? Training ended hours ago."
Eren swallowed, suddenly aware of how dry his mouth had become. "We, uh—we found something. Something that could help you."
Mikasa tilted her head slightly, her dark eyes narrowing just enough to make Armin shift uncomfortably beside him. "Help me how?"
Eren hesitated, glancing at Armin for support. The blonde strategist sighed, adjusting his glasses before stepping forward. "We discovered a… *unique* herb. It enhances physical capabilities when combined with intense training. But it only works on Women.“
Mikasa’s gaze flicked between them, her expression unreadable.
The evening air was thick with the scent of sweat and damp earth, the distant shouts of soldiers fading into the hum of crickets. The last rays of sunlight caught the sweat glistening on her arms, highlighting the definition of her muscles—muscles that had already surpassed most of the Survey Corps.
Eren swallowed hard, his throat tight. "It’s not just about strength," he said, his voice rougher than he intended. "It’s about… evolution. You could be even stronger. Even more…"
Armin cleared his throat, stepping in before Eren could dig himself deeper. "The herb reacts to intense physical exertion. It accelerates muscle growth, endurance, recovery—everything.
But it’s not just about physical strength. It’s about unlocking potential."
Mikasa’s dark eyes narrowed slightly, her gaze flicking between Eren and Armin. "And you want me to test it."
Eren nodded, his fingers twitching at his sides. "You’re the strongest fighter we have. If this works, it could change everything."
Mikasa exhaled sharply, her breath warm in the cooling air. "And if it doesn’t?"
Armin adjusted his glasses, his voice careful. "Then we’ll know it doesn’t work. But we won’t know unless we try."
A beat of silence stretched between them, the only sound the distant clatter of training equipment being stored away. Her huge breast rose and fell with her steady breathing, the fabric of her uniform straining slightly against the curves of her chest. Eren’s gaze flicked down involuntarily, then back up to her face before he could be caught. Mikasa noticed anyway. Her lips curled into the faintest smirk, one that made Eren’s pulse jump.
"You’re staring again," she said, her voice low and amused.
Eren cleared his throat, forcing his eyes to stay on her face. "I was just... admiring your form. You’ve been training harder than ever."
Armin shot him a look that clearly said *shut up before you make this worse*, but Eren ignored it. She will take the herb and they will meet next week so she knows her data .
The next week, Mikasa was even more muscular than before. She was standing in the middle of the training grounds, her back turned to them as she stretched, her muscles rippling beneath her skin. Her black hair was pulled back into a tight ponytail, and her uniform was slightly tighter than usual, hugging her curves in all the right places. Eren couldn’t help but stare, his heart pounding in his chest. He had never seen her like this before—so strong, so powerful, so *dominant*.
Armin nudged him again, this time with more force. "Focus," he hissed under his breath.
"You're staring like a lovesick puppy."
Eren tore his gaze away from Mikasa's sculpted back, but not before she turned slightly, catching him mid-stare. Her dark eyes gleamed with amusement as she arched a perfect eyebrow. "Something on my back, Eren?" she asked, her voice smooth as silk.
Armin groaned beside him. "You're making this worse."
Eren cleared his throat, forcing his eyes to meet hers. "No, just... admiring your progress. You look... incredible."
Mikasa smirked, rolling her shoulders back in a way that made her biceps flex deliciously. She blushes slightly at the compliment, but her voice remained steady as she turned to face them fully. "You two look like you've been up all night," she observed, her dark eyes flicking between them. "What's the plan today?"
Eren swallowed hard, his throat suddenly dry. The sight of her like this—so strong, so *commanding*—made his pulse race in a way that had nothing to do with strategy. "We, uh… we wanted to see how you’ve been feeling since last week. Any changes?"
Mikasa’s lips curled into a knowing smile.
"You mean besides the fact that I can bench press twice my body weight now?" She flexed her arms casually, the muscles in her biceps and triceps swelling beneath her skin. The fabric of her uniform strained against her shoulders, the seams threatening to give way at any moment. Eren’s throat went dry as he watched the way her body moved—fluid, powerful, *perfect*.
Armin, ever the voice of reason, cleared his throat. "That’s… impressive. But we need to document the effects. Any other changes? Dizziness? Nausea? Uncontrollable urges to—"
"To *what*?" Mikasa interrupted, her dark eyes narrowing slightly.
"To what, Armin?" she repeated, her voice low and smooth. There was a challenge in her tone, a hint of amusement that made Eren’s pulse quicken.
Armin adjusted his glasses, his fingers twitching nervously. "Uh. Nothing. Just… general side effects. You know. The usual."
Mikasa’s face remained stoic , but there was something in her eyes—a flicker of something deeper, something that made Eren’s stomach tighten. She stepped closer, her boots sinking slightly into the damp grass. The air between them thickened, charged with something unspoken.
"You’re hiding something," she said, her voice low, almost a whisper.
Eren swallowed hard, his throat dry. He could feel the weight of the herb in his bag, pressing against his side like a secret. "No, we’re just—"
"Curious," Armin finished quickly, stepping forward before Eren could dig himself deeper. "We’re just curious about the effects.
That’s all," Armin said, his voice steady despite the way his fingers twitched at his sides. The evening air was thick with the scent of damp earth and the faint metallic tang of sweat from the training grounds. The last remnants of sunlight painted the sky in deep oranges and purples, casting long shadows across the field where Mikasa stood.
Mikasa’s dark eyes flicked between them, her expression unreadable. The way she held herself—shoulders back, muscles coiled like steel—made Eren’s pulse quicken. She had always been strong, but now there was something *different* about her. She is still shy and stoic but her presence was overwhelming. The way her muscles shifted beneath her skin, the way her uniform strained against her growing curves—it was intoxicating. Eren’s fingers twitched at his sides, his pulse quickening as he forced himself to keep his gaze steady.
They test mikasas new strengh and write down her new sizes like height and bicep. She is now built like a Bodybuilder but she will grow way more
in the future. Eren is in awe of her new body. Armin is impressed but he is more focused on the data. Mikasa is still shy but she is more dominant than before. She is more protective of eren and she is more possessive of him. She is more aggressive in training and she is more assertive in her speech. She is more confident in her abilities and she is more willing to take charge. She is more dominant in her personality and she is more protective of eren.
a few days later , the three of them were back at the training grounds. The air was thick with the scent of sweat and grass, the late afternoon sun casting long shadows across the field. Mikasa stood in the center of the obstacle course, her muscles gleaming with a light sheen of perspiration. She had grown even more since their last meeting—her biceps bulging beneath the tight fabric of her uniform, her thighs thick and powerful as she moved with effortless grace.
Eren couldn’t take his eyes off her.
Armin nudged him again, his voice low. "You’re drooling."
Eren wiped his mouth instinctively, though he knew he wasn’t.
Not literally, anyway. But the way Mikasa’s biceps flexed as she adjusted her stance—her uniform straining against the swell of her chest—was making his throat dry. He swallowed hard, forcing his gaze upward.
Armin sighed beside him. "You’re making this awkward."
Eren shot him a glare. "I’m not doing anything."
Mikasa turned then, her dark eyes locking onto his. There was something different in her gaze now—something sharper, more knowing. "You’re staring again," she said, her voice low and smooth.
Eren opened his mouth to protest, but the words died on his tongue. Because she was right. He *was* staring.
And he couldn’t stop.
Mikasa’s muscles had grown even more defined since their last meeting, her biceps straining against the fabric of her uniform, her shoulders broad and powerful. The way her uniform clung to her curves—her chest now fuller, her waist narrower—made his pulse quicken. He had always admired her strength, but this was something else entirely.
Armin cleared his throat beside him, his voice low. "You’re making it obvious."
Armin muttered under his breath, elbowing Eren hard in the ribs. "She’s going to think you’re some kind of pervert."
Eren rubbed his side, shooting his friend a glare before turning back to Mikasa, who was now stretching her arms above her head, the fabric of her uniform pulling taut across her swelling chest. The way her muscles rippled beneath her skin as she moved was hypnotic, and Eren couldn’t help but stare. He cleared his throat, forcing himself to look away. "We should probably get started."
Mikasa lowered her arms, her dark eyes locking onto his with an intensity that made his pulse quicken. "You wanted to train alone?" she asked, her voice smooth and low. "Just the two of us?"
Eren nodded, his throat suddenly dry. "Yeah. We thought it would be better if we kept this between us for now.
Just to see how it develops before we tell anyone else."
Mikasa's dark eyes narrowed slightly as she studied them, her fingers tightening around the strap of her bag. "You're hiding something," she said flatly. "I can tell." His dick twitched uncontrollably now, betraying him in the most inconvenient way possible. He shifted his weight, hoping the movement would go unnoticed, but Mikasa's sharp gaze missed nothing.
Armin, ever the voice of reason, stepped forward with a forced smile. "We're just being cautious," he said, his voice too high-pitched to be convincing. "You know how the higher-ups are about untested substances. We don't want to cause any unnecessary panic."
Mikasa's lips pressed into a thin line, her eyes flicking between the two of them.
"You're hiding something," she repeated, her voice low and dangerous.
Eren’s dick throbbed visibly again, straining against the fabric of his pants in a way that was impossible to ignore. He shifted uncomfortably, his face flushing as he tried to subtly adjust himself, but Mikasa’s sharp gaze caught the movement. Her eyes darkened, and for a moment, Eren swore he saw something flicker in her expression—something between amusement and irritation.
Armin, ever the strategist, cleared his throat and stepped between them, his shorter frame barely blocking the view of Eren’s obvious arousal. "We’re just being cautious," he said, his voice too chipper to be natural. We don’t want to cause any unnecessary panic."
Mikasa’s dark eyes narrowed further, her fingers tightening around the strap of her bag.
Her gaze lingered on Eren’s crotch for just a fraction of a second longer than necessary, long enough for him to feel the heat rise in his face. The corner of her mouth twitched—whether in amusement or irritation, he couldn’t tell. Armin, ever the mediator, cleared his throat loudly, stepping between them with forced casualness.
“Right, well,” Armin said, adjusting his glasses with fingers that trembled slightly. “We should probably get started. Before, uh… before anything else happens.”
Eren swallowed hard, his throat dry. He could feel the weight of Mikasa’s stare still burning into him, even as she turned her attention back to the training grounds. The way her muscles shifted beneath her uniform as she moved—fluid, powerful, *commanding*—made his pulse quicken. He had never seen her like this before. Not just stronger, but *different*. More confident. More *dominant*.
That was the word that kept circling Eren’s mind as he watched Mikasa’s muscles ripple beneath her uniform. The fabric strained against her growing curves, the seams threatening to give at any moment. He swallowed hard, his throat dry. Armin cleared his throat loudly, stepping between them with forced casualness. "Right, well," Armin said, adjusting his glasses with fingers that trembled slightly. "We should probably get started. Before, uh… before anything else happens." He shot Eren a pointed look, one that clearly said *stop staring before she notices* (though of course she already had). With that, Armin turned on his heel, his short legs carrying him away from the training grounds with uncharacteristic speed. "I'll be back in an hour," he called over his shoulder, not waiting for a response. "Don't do anything stupid."
The moment he was out of earshot, the air between Eren and Mikasa thickened. The late afternoon sun cast long shadows across the grass, the only sound the distant clatter of training equipment being stored away. Mikasa's dark eyes locked onto Eren's, her expression unreadable. The way her muscles shifted beneath her uniform—her biceps straining against the fabric, her shoulders broad and powerful—made his pulse quicken.
"You're hiding something," she said again, her voice low and smooth.
"You're making it obvious." "I'm not doing anything." "You're staring again," she said, her voice low and smooth.
The way her dark eyes locked onto his made Eren’s pulse quicken. He swallowed hard, his throat suddenly dry. "I was just... admiring your progress," he managed, though his voice sounded rough even to his own ears. The air between them was thick with tension, the scent of sweat and earth mingling in the evening breeze. Mikasa’s lips curled into a faint smirk, though her expression remained otherwise unreadable. "Progress?" she repeated, arching a perfect eyebrow. "Is that what you call it?" Eren’s fingers twitched at his sides, his gaze flicking down to the way her uniform strained against her growing muscles—her biceps thick and defined, her shoulders broad and powerful.
The fabric of her top was already pulling tight across her chest, the seams threatening to give way at any moment. "I just meant—" he started, but Mikasa cut him off with a sharp tilt of her head.
"You don’t have to explain," she said, her voice low and smooth. "I know what you’re thinking."
Eren’s pulse quickened. "You do?" "You’ve always been terrible at hiding your thoughts, Eren."
He opened his mouth to protest, but the words died on his tongue. As mikasa kisses him , his dick throbs uncontrollably, straining against the fabric of his pants. He can feel the heat of her body pressing against him, the sheer power in her muscles as she holds him close. Her lips are soft but demanding, her tongue slipping into his mouth with a confidence that makes his knees weak. He can taste the faint metallic tang of sweat on her skin, the scent of her shampoo mingling with the earthy musk of the training grounds.
When she finally pulls away, her dark eyes are burning with an intensity that makes his breath catch. She is niw way taller than him and she is looking down at him with a smirk. "You’re not the only one who’s been thinking about this," she murmurs, her voice rough with desire. "I’ve been watching you too, Eren. Watching the way your eyes linger on me. The way your pulse quickens when I move."
Eren swallows hard, his throat dry. "Mikasa, I—"
She doesn’t let him finish. Instead, she steps closer, her body pressing against his, her muscles flexing with every movement. The heat of her skin radiates through the thin fabric of his shirt, and he can feel the power in her arms as they wrap around him.
Her grip is firm, possessive, and he can’t help but let out a small gasp as her fingers dig into his back, pulling him closer. The scent of her—sweat and something sweetly floral—fills his senses, making his head spin.
“You’ve been staring,” she murmurs against his lips, her voice a low, teasing growl. “Admiring. Wanting.”
Eren’s breath hitches. He’s always known Mikasa was strong, but this—this is something else. The way her muscles ripple beneath her skin, the way her uniform strains against her growing curves—it’s intoxicating.
Eren’s pulse quickens as Mikasa’s lips crash against his, her tongue demanding entry with a hunger that makes his knees weak. Her grip on him tightens, her fingers digging into his back with a possessiveness that sends a thrill down his spine. She is now way taller than him, her towering frame casting a shadow over him as she looks down with a smirk.
Eren loves it—loves the way her muscles ripple as she moves, the way her uniform strains against her growing curves, the way she dominates the space around them with effortless power. His pulse quickens as her lips crash against his again, her tongue demanding entry with a hunger that makes his knees weak.
She lifts him up effortlessly, her arms wrapping around his waist as she presses him against the nearest wall. The rough brick digs into his back, but he barely notices—his entire focus is on the way her body feels against his, the sheer power radiating from her muscles as she holds him there with ease.
Eren’s breath comes in short, sharp gasps as Mikasa’s lips trail down his neck, her teeth grazing his skin just hard enough to make him shiver. The way her muscles flex with every movement—her biceps bulging, her shoulders straining against the fabric of her uniform—is intoxicating. Then her muscles tesr trough the fabric of her uniform, the seams threatening to burst at any moment. Eren’s pulse quickens as he watches the way her body moves, the sheer power radiating from her with every step. Her clothes tear appart as she flexes her muscles, the fabric no longer able to contain the sheer mass of her physique. Her muscles ripple beneath her skin, her biceps bulging, her shoulders broad and powerful. The way her uniform strains against her growing curves—her chest now fuller, her waist narrower—makes his breath hitch. He has never seen her like this before.
Mikasa’s dark eyes lock onto his, her gaze intense, almost predatory. The way she looks at him now—like she could devour him whole—sends a shiver down his spine. Her body has lost its softness and been replaced with something harder, something *stronger*. The uniform she was wearing moments ago now lies in tatters at her feet, the fabric torn apart by the sheer power of her transformation. Her muscles gleam in the fading sunlight, every curve and contour of her body now defined by raw, unyielding strength.
Eren’s breath catches as he takes her in. Her biceps are thick, veined, and straining against the air itself. Her shoulders are broad, her chest full and firm, her waist narrow before flaring into powerful hips and thighs that could crush stone. The growth herb has done more than just increase her muscle mass—it has *perfected* her. She much muscle mass than before, her body a masterpiece of raw, sculpted power. Her black hair, still tied back in a loose braid, frames a face that is both fierce and strikingly beautiful. Her dark eyes burn with an intensity that makes Eren’s pulse quicken, and her lips—soft and full—curve into a smirk as she watches him react.
Eren’s breath comes in short, uneven gasps as he takes her in. The way her muscles ripple beneath her skin, the way her uniform—now in tatters—barely clings to her body, the way her every movement radiates dominance. She is no longer just Mikasa, his childhood friend, his protector. She is something *more*.
Something *greater*.
Eren’s fingers twitch at his sides, his throat dry as he struggles to find words. The air between them is thick with the scent of sweat and something sharper—something *alive*. The last rays of sunlight catch the sheen of Mikasa’s muscles, highlighting every curve, every ripple of power. Her biceps flex as she shifts her weight, her triceps swelling beneath her skin. The way her uniform—what’s left of it—clings to her body makes his pulse quicken.
"You’re staring again," she murmurs, her voice low and smooth.
Eren swallows hard. She is complete topless now, her huge breast on full display. The sight of her like this—muscles rippling, skin glistening with sweat, her dark eyes locked onto him with an intensity that makes his breath catch—is almost too much. His fingers twitch at his sides, his pulse hammering in his ears. Not just stronger, but *dominant*. *Commanding*.
Mikasa steps closer, her bare feet sinking slightly into the damp grass. The way her muscles shift with every movement—her biceps flexing, her shoulders rolling back with effortless power—is hypnotic.
The fading sunlight catches the sheen of her sweat-slicked skin, highlighting every curve, every ripple of definition. Her biceps bulge with each breath, her triceps straining as she flexes her fingers at her sides. The way her uniform—what’s left of it—clings to her lower half, the fabric barely containing the sheer mass of her thighs, makes his throat tighten.
Mikasa’s dark eyes burn into him, her gaze sharp and knowing. "You like what you see?" she asks, her voice low and smooth, laced with something dangerous.
Eren’s mouth goes dry.