TMNT FANFIC: Lost and found

Chains

Donnie groaned as his eyes flickered open, haze fading as he blinked to fix his blurred vision. The screams of those around him suddenly became audible, plummeting him back into reality as he scanned the room and his surroundings.
LH, Mikey, Raph and a few other indistinguishable faces were lined up along the wall next to him, each tugging at the chains around their wrists which hung from above them.
Breath quickening, Donnie tried to move his own arms, panicking as they hit the cold metal that restrained him.
"What's...what's going on?" He spluttered, staring at Raph through the darkness for an answer.
His older brother stopped struggling for a second, a small smile of relief crossing his features.
"You're finally awake." He sighed, squinting slightly. "I dunno where we are, or how we got here. All I remember is the train-"

"So you're all awake." A gravelly voice echoed around the room. A bright light burst through the doors, along with a brooding figure, receiving multiple groans as the newfound brightness burnt their eyes.
"W-WHO ARE YOU!" Raph yelled, chains rattling as he moved towards the figure.

"Who am I?" The voice repeated, an ominous laugh following his question. Donnie felt a shiver run up his spine as the man drew closer, unable to see his face behind his mask. "I am the fear that festers within each of you. The darkness that lurks in the corners of your minds. The key to unlocking pure power...your power.. So I ask you, who do you think I am?"

"Oroku Saki." Donnie breathed, ignoring his brother's stares. He knew they had each been informed of their father's dishonourable brother, but were unaware of his presence in New York.
"Yes." The man raised his arms, clutching the sides of his mask. He tore it from him face, discarding it to the side of the small room.
Donnie heard the strangers from across the room gasp, but didn't dare utter a word as he looked at Saki's face.
His black hair was short, a similar shade to his eyes. But what was disturbing were the deep scars that covered his face, trailing down towards his chest.
"You see these." He ran a hand over the healed wounds. "These were given to me by a mere child. A boy who couldn't control his powers. I can't say I blame him for sending multiple shards of glass flying towards me, or for the concrete he left me crushed under." Saki lifted his shirt only slightly, revealing the purple and blue scarred flesh below.
"You know, I had a brother who had powers. He was able to protect himself while the boy's in our neighbourhood would beat me up. How is it fair that you mutants get to defend yourselves while we're left vulnerable?"
He paced before them, flicking a switched on the wall nearby  which opened up a giant mirror in front of them. Donnie stared at it, wincing as he watched the blood drip down his face from a cut he was unaware he had.
"Do you know what we do here." Saki didn't direct the question to anyone, not waiting for an answer. "We've been experimenting and torturing mutants to try and find a way of using their powers for our own needs. But despite this, I just don't get why you rebels don't like us-I mean sure-almost all the mutants we test on die but we share the same enemy." A twisting smile was plastered on his face once more as he turned to look at the mirror.
"Monster." Raph spat, grunting as the metal dug into his skin.
Saki turned to look at them once more, shaking his head slightly.
"Oh I'm not the monster." He gestured to his scars once more, before jabbing a finger at Raph's chest. "Do you want to know who did this to me?"
Saki tore off his sleeves, flashing around the purple and blue spindles that ran down it.
They were the markings of lightning, burns of pure electricity.
"It can't be." Donnie murmured, the pieces all adding up in his mind. Saki moved over to him, eye contact unwavering.
"You know who it was. Don't you." He spoke with certainty.
"What's he talking about Donnie?" Raph growled, glaring at Saki.
"...Leo." Donnie swallowed, attempting to sort his thoughts as multiple theories flooded his mind, all  leading to the same conclusion.
"What? That's impossible. Leo's dead." Raph chocked, shaking his head multiple times, but Donnie could tell that he to had realised the truth. He was just denying it out of sheer disbelief.
"No, no he's not." Saki laughed again, shaking his head incessantly. "I'm surprised you do not recognise me Raphael, as I am the one who dragged your brother away for execution."
Raph's eyes widened almost instantly, flames igniting from his fists. The sparks quickly diminished however, leaving mere puffs of smoke that trailed away from Raph's hands.
Upon closer inspection, Donnie groaned inwardly once he realised the chains that bound them were forged from limestone.
"I had been working against your kind, wanting to rid the world of your filth, but it was when I saw the sheer uncontrollable power your brother possessed that I had second thoughts. I could never execute something as valuable as that. So I decided to burden him with a fate worse than death." Saki sneered, walking back towards were he'd left his helmet.
"He became my first experiment, and survived every test. His power has grown stronger over the years yet he's still unable to control it. Leonardo was the only mutant able to resist the torture trials and injections, yet he still only uses his powers to protect some little girl. So I learnt from my previous actions and tortured his mind instead. That caught his attention."
"WHAT DID YOU DO TO MY BROTHER!" Raph screeched, eyes burning as he tugged against his restraints, blood dripping from his chaffed wrists.
"He was just a kid." Mikey's voice murmured from across the room. He was staring at the ground, simply hanging from his cuffs. "HOW COULD YOU DO THAT TO A LITTLE KID!" He looked up, tears slipping from his baby blue eyes as he shouted.
"I can't believe he's alive." Donnie uttered, still trying to comprehend all that he was being told.
"You don't believe me?" Saki shrugged, moving toward the switches on the wall. "How about I just show you."
With one click, the mirror morphed into a glass screen, displaying a different sight. Donnie shook, eyes watering as he tried to overcome all the emotions flooding through him.
"L-Leo.." He croaked, staring at the limp body lying in what seemed to be a cell, chained the wall with his head facing the ground. He could've sworn his heart stopped when the boy lifted his head, deep Sapphire blue eyes meeting his own. But there was no recognition.
"I-it's a two way mirror." Donnie sighed, looking back at Saki. "He's hurt...Leo hurt, I need to help him." Heat rose to his cheeks as Saki only responded with a look of mock sympathy. He could feel the anger bubbling in his stomach, not bothering to swallow it down as it exploded.
"HOW DARE YOU HURT MY BROTHER IN ANY WAY, WHETHER PHYSICAL OR PSYCHOLOGICAL! HOW COULD YOU TORTURE SUCH AN INNOCENT KID, JUST WAIT 'TIL I'M OUT OF THESE RESTRAINTS, THEN YOU'LL TRULY LEARN THE MEANING OF FATE WORSE THAN DEATH!" His throat was raw by the end. Both Mikey and Raph were staring at him, astounded by their brother's sudden outburst, but nodding in agreement. It wasn't in his nature to scream at anyone, or to exchange words with such venom in any means. So when Donnie was livid, something was really wrong.
"Don't worry dear nephew." Saki grinned, tapping the window slightly. "You can tend to him all you like tomorrow.....when you join your brother in the trials."