Harry Potter : Reincarnated as The Greatest Wizard

Placing the clipboard aside, Alex slid on a set of knuckle-dusters, each rune-inscribed to enhance pain when striking. He didn't hesitate, aiming a calculated punch straight at Torquil's chest wound. The force sent fresh waves of agony through Torquil's body, making him arch against the floor in a futile attempt to escape. Already weakened from the earlier ordeal, Torquil let out a sound that could only be described as primal—raw, guttural, and filled with despair. The runes on Alex's knuckles amplified the pain, turning every blow into an unbearable torment.

The onlookers were frozen in place, their faces pale as Torquil's screams rattled through the room. One of them began trembling uncontrollably, and another gripped the edge of the table for support, their knuckles white. Alex, unfazed, checked the instrument's dial again, nodding in satisfaction. "Fascinating. Emotional distress seems to cause slight fluctuations, but the mana reserve remains relatively stable. Good data."

Torquil bared his teeth, gritting them against the searing pain radiating from Alex's brutal punch. Despite the agony, his glare remained sharp, his eyes blazing with venomous defiance.

He scribbled a few more notes on his clipboard before turning back to Torquil, his expression as calm and detached as ever. "Thanks for your cooperation. I'll heal you up now. Let's just say you've at least been helpful for once in your life.."

Alex pulled the suction pump of the oversized syringe, and blood slowly began to flow back through the infusion tube into the empty vial. His eyes stayed glued to the values on the dashboard. As the blood filled the tube, the pointer on the instrument began to retract, inch by inch, from its initial reading of 412 to 410. By now, Alex had extracted nearly 40 milliliters of blood. 

"Yaxley's body holds around 4,000 milliliters of blood. Drawing out just one percent seems to lower his mana levels by about two ticks, roughly 0.5%. That means blood contains nearly half of a wizard's magical power. Is this true for all wizards, or do individual differences exist? I'll need to test more subjects to confirm," Alex muttered, already forming plans in his mind.

Without delay, he returned Yaxley's blood, wiped down the instrument half-heartedly, and moved on to the other four Death Eaters. Infection concerns didn't faze him in the slightest. He grabbed the next one, plugged the needle in, and repeated the process. After a full round of blood draws and measurements, Alex came to a definitive conclusion: a wizard's blood contains about 50% of their magic power.

Alex's eyes lit up as he reviewed the data. "If magic power is so concentrated in the blood, I might not even need invasive tools to measure mana in the future. A simple blood test could work just as well." He couldn't suppress his excitement as a solution to a long-standing problem dawned on him.

Currently, his measuring instrument required a large contact surface and deep insertion into a subject's body for accurate results—a method as terrifying as it was impractical. But this new approach could make things simpler. 

"First, I'll need to craft an alchemy tool capable of detecting total blood volume. Then I'll draw a small sample to measure its mana concentration. Multiply that by the total blood volume and double it for accuracy—boom, you've got the wizard's total mana reserve." Alex was practically giddy, sketching out calculations in his head.

He glanced at the group of restrained Death Eaters, who were too weak to protest. To Alex, they were treasures—living, breathing test subjects who could help him perfect his methods. "I'll need to run more tests next time to fine-tune the numbers," he decided, a grin spreading across his face.

Karkaroff, trembling in his restraints, shuddered at the sight of Alex's expression. "He's smiling again! This maniac treats us like toys! If someone—anyone—saves me, I'll sell my soul," he whispered, eyes squeezed shut as he prayed desperately to any dark force that might listen.

Alex clapped his hands, his voice cutting through the tense silence. "Alright! That wraps up phase one. Time for phase two!" His enthusiasm sent another wave of dread through his unwilling subjects.

Alex approached his workbench and picked up a peculiar metallic object. It looked like a segmented chain, woven together from nine flat, enchanted rods. Despite its crude appearance, it carried a certain elegance, the charm inscriptions glinting faintly under the dim light.

Carefully, Alex placed the chain on the ground and whispered an incantation. The chain writhed, twisting and coiling until it transformed into a small, silver snake with an unnervingly smooth, metallic sheen. The creature flexed its body once before darting toward Yaxley with unnatural speed.

Alex wasted no time. He inserted the measuring device back into Yaxley's body and watched the readings closely. The silver snake wrapped itself tightly around Yaxley, and the effects were immediate. Yaxley began to shiver violently, his body temperature dropping as though he'd been plunged into an ice bath. The instrument displayed a rapid decline in mana reserves—clearly visible, even to the naked eye.

Holding a stopwatch in one hand, Alex alternated his gaze between the timer and the instrument. "Eighteen Lum of mana loss per second," he noted aloud, his voice filled with satisfaction. "That means each spell etched into the snake drains two ticks per second. That's four times more efficient than my earlier tests on Travers."

Yaxley's shivering turned into uncontrollable convulsions as his mana reserves plummeted. In just 23 seconds, the instrument showed that his magical power had been completely drained. Yaxley slumped forward, his skin pale, his breathing shallow. Meanwhile, the silver snake maintained its firm grip, further lowering his body temperature.

"This is promising," Alex mused, jotting down the results. "The Spirit-Binding Snake not only drains mana quickly but also immobilizes the target and disrupts their focus with its cooling effect. Perfect for combat and containment scenarios. I might upgrade it into a full-body net once I get better materials."

Yaxley couldn't quite grasp what Alex had done to him. The moment the metal snake made contact, he felt his magic draining rapidly, a bone-deep chill creeping over him. It was as if his body was surrendering to the frost. The thought crossed his mind—perhaps freezing to death like this wouldn't be so bad. It might even be a relief, a final escape from this awful teenager who seemed to revel in tormenting him.

But just as he began to embrace the idea of death as a way out, the chilling sensation started to fade. Warmth returned to his body, gradually replacing the cold. Alex had retracted the silver snake and, rather thoughtfully, cast a warming spell on him. 

"So that's it, huh? You won't even let me die if I wanted to…" Yaxley muttered, his voice trembling. His lips curled into a strange smile, one that didn't reach his dull, glassy eyes. He stared blankly at the ceiling, the weight of his mental and physical torment dragging him closer to the edge of madness. A soft, unsettling chuckle escaped him, building into a disjointed laugh.

Alex, watching this peculiar reaction, scratched his head in confusion. "What's with that smile? I warmed you up, didn't I? Shouldn't you be grateful or something?"