Fury

Two golden eyes stared.
You were like a butterfly. So beautiful and delicate. So swift and quick when you used your 3DMG.
So...fragile. Like he could reach out and crush you with one fist. Rip your wings off if you tried to get away from him.
He shook his head and swallowed thickly, looking down. These dark thoughts had been getting to him recently, and he didn't know why. He knew he was bipolar, and he knew he had this side to him that he never wanted to show anyone. A frightening side that he wanted to deny existed when he was feeling sane.
The soldier was a noble man, a big brother to the smaller Survey Corps members. Someone who could be relied on, especially in a pinch.
The warrior was cruel and ruthless, happy to kill and obliterate whatever needed destroying, so long as he got what he wanted.
You were something he wanted desperately, and it was as if that warrior within him was just ready to climb out and take hold of his skin at any moment. When you came near him he could feel that urge to reach out and grab your wrist in his hand. Pull you close for a hug or even a tender kiss if you let him.
Break it if you tried to pull away.
It would be so easy too. As he raised his weary head and looked across the training grounds, he could see how hard you were slashing at that small wooden target with your blades. Kudos to you, for boy were you working up a sweat out there, and you certainly knew what you were doing. Not good enough to be offered a spot in the Military Police, granted, but who wanted that anyway? Especially not him, considering you'd only have been separated if that had happened.
No, it was better to have you here now, where he could admire your strength while at the same time know it would mean nothing against someone like him. There was a reason why he was only ever paired up against either someone who was close to his size or Annie when they were all sparring. A petite little thing like you, someone who wasn't a murder machine like that ice princess? Well...you'd be ruined.
He bit down on his nails and picked at them anxiously while he continued sitting on the sidelines. This was just spare practice so Shadis only came by now and again to check up on things. He claimed to Bert that he was going for a drink of water, and yes, he'd downed a little while here, but it was primarily a move he had made to get closer to you.
Watch you. Watch you ceaselessly.
Wonder what you would look like in his bed.
If only. Reiner knew you didn't love him. You were smitten with Armin and that much was so fucking obvious it made him sick. Your type was clearly the exact opposite of how he was himself. Armin was small, delicate, intellectually inclined. He liked discussing books and bird types with you, picking flowers to make into little crowns for the top of your head.
Reiner was none of those things, he did none of those things. He was tall and brawn, muscled and intimidating. Most of the time he had an expression like he was less than subtly pissed off, and he certainly couldn't have pointed out the difference between a bluebird and a bluebell.
It was a competition he couldn't win.
Which was why that side of him was so adamant.
He could just...take you by force, couldn't he? Grab some rope, grab you, find a quiet spot and bingo. Keep you there forever where no big-eyed blondie could follow. The danger was that he was afraid to even put his hands on you at this point. The burning desire had seethed there for too long, unspoken of and unreleased, to the point where he felt he might flip out and hurt you somehow if you even came close to him.
A butterfly could be so easily killed. You weren't on his death list. You were something he lived for, so even when it came time for him and his Titan companions to tear this whole world down, he'd rescue you from the rubble. You and only you. Then you'd be together alone.
Too bad that was a long way off from now. He had to bide his time and play pretend, all the while desperately wanting to fast forward to that moment where he could hold you in his palms. It would be all the easier at Titan size too, to just make you do whatever he wanted. Maybe it wasn't fair to toy with something so much smaller...but treating you like a doll would be perfect. Only then would you truly be his own, his property, his completely. His possession.
Right now you really were like some gorgeous bug he couldn't catch, flittering around freely no matter where he swung his net. His fists clenched by his sides and he made himself stand up. Better to leave now, things were wrapping up and he didn't want you to see him hanging around like this. He picked up his water canister and turned to go-
“Reiner!”
His whole world froze. Just like that, the part of himself he hated so was whispering cruelly in his ear.
“Here she is...let's say hi...”
His lips pursed, teeth emerging just to bite down on the bottom and tug it taut beneath. He drew slight blood but didn't care. He just didn't want to turn around and see you.
Yet at the same time he did. He wanted to look at your face, your body, imprint every pore in his mind so he might never forget it.
“Reiner, are you okay?”
Your hand touched the middle of his back and you immediately noticed how tense he was. He almost seemed to be quivering.
“...Did you overwork yourself?” your voice showed evident concern, as you shifted around to try and look at his face. When you caught sight of his profile you were alarmed.
His jaw was clenched so tight his teeth must have been grinding together, you could see it by the line. His lips were an uneven wiggle, as if he were struggling to hold back a laugh, or a maniacal grin perhaps. His eyes showed that same mania too, one pin-prick pupil snapping over to the corner just so he could see you. There wasn't a hint of that gold anymore.
Cautiously, you moved your hand away from him and took a step back. The tall blonde looked fit to combust, like he was barely holding something within. It was quite frightening, normally he was so calm and stoic, you had never seen him this way before.
“R...Reiner?”
That's it. Say my name again.
“...”
Oh wait. You will. Plenty of times...
“...” Reiner turned slowly. That expression didn't change much initially, but suddenly that mouth of his split apart into a grin that chilled you right through. Never had you seen him look so deranged, and suddenly every instinct in your body was screaming for you to run.
An excuse. You'd give him an excuse, and leave. Whatever was happening right now, you wanted no part in it.
“I-I should...I was meeting Armin after practice, so I should really-”
“Go?” Reiner finally spoke. It was his deep and rumbling voice, certainly, but something was off about it, just like his expression. Like something inside him had been tilted sharply. As if there were some force pressing and pushing to emerge, and it was slowly starting to show itself bit by bit.
“Y-yes-”
“Go meet Armin? Oh...I'm not surprised.” Reiner took a calm step towards you, and you would have stepped back had sudden fear not frozen you in place. These were the same alarm bells that went off whenever you saw a Titan. And honestly, with that hungry expression, he kind of looked like one now.
Your eyes darted over to the training area instead. Your blades weren't easily accessed, they were way over there with your cloak and water bottle. You would have tried to think of some different plan had Reiner's hand on your cheek not snapped you back to reality.
“No-!!” you squeaked and immediately clutched his wrist with both hands and shut eyes, as he gently pressed his fingers against your skin. Yet his voice spoke sweetly to you:
“Don't be afraid [Y/N]. Look...I'm treating you so gently.”
Hesitating, you slowly loosened your grip and looked up at him. It was as if you had imagined his change from before. Like it had just been an illusion brought on by exhaustion. Perhaps it only had been.
He certainly looked like himself again, even a little softer than usual. His features were quite hard and carved, but they looked more loving now. This was another side you hadn't seen from him before, but it was far better than that other...thing.
“...Reiner...what's going on with you?” you asked him nervously, as he cupped your cheek fully. His large hand wasn't going away, you knew that much, but at least he wasn't doing anything bad with it.
“Nothing really. I've just been missing you lately. You seem to be spending a lot of time with Armin after all, so things have been very distant between us.”
Little had you noticed until right now, Reiner's shadow upon you had grown by a bit. He was much closer than before, and when you shifted even slightly you could feel the bark of a tree behind you, bumping your spine. You'd been so startled you hadn't even noticed him cornering you in this small forest by the training grounds. Those blades were even further away now.
“Well you've been making it distant too. I mean...y-you kind of went silent on me-”
That silence greeted you now. It was like before, only even eerier. You kept your head down, not wanting to look up at his face, not wanting to see that furiously insane visage again. You didn't want it to be real after all.
His hand stroked your cheek gently and you cringed a little. Reiner was handsome, capable, but you couldn't love him, not when you had Armin.
Yes...Armin was who you had fallen for. Maybe in another life you could have been with this tough fellow, but in this lifetime you were taken by the gentle charms of Armin. Nobody else.
You shut your eyes and just admitted it before things went any further. It would be enough to just be honest, right?
“I'm sorry Reiner, but I can't! I have a boyfr--”
The world spun.
At first you didn't know what had happened. Everything was sky and sand and sky again, a whirlpool of varying colors. Then finally that same sand came rushing up to kiss you, and you slammed down against it with a wheeze. Turning your head and coughing, you came to realize that you'd been chucked halfway towards where you'd been doing your training, not too far from the benches.
Your neck ached and throbbed. That was how he grabbed you. Turning on your back and trembling to sit up, you whimpered and cowered as you saw Reiner right there, the darkness falling across you again. However blue the sky might have been, it turned grey right then and there, as if it's mood had suddenly shifted.
A pair of practically glowing golden eyes stared down at you from that stormy backdrop, and you heard a couple of bony cracks.
That grin was back again.
“We haven't had a chance to spar yet, have we [Y/N]?"