The Greatest Assassin Gets Reincarnated in Tensura

As Arion sat up, he could immediately feel the differences in his body. His once youthful features had matured, taking on a more refined and commanding presence. His form, still lean but now built with a subtle yet undeniable strength, exuded an aura of absolute authority.

The most striking change was his hair—what was once a deep shade of midnight black had turned an ethereal white, almost glowing under the dim light. It was long, cascading past his shoulders, yet perfectly controlled, with strands flowing like silk as if responding to his very will.

His eyes, now a haunting crimson, carried a depth that hadn't been there before. They weren't just red—they shimmered like liquid rubies, swirling with unfathomable knowledge and power. A single glance was enough to make even the strongest beings hesitate, for within them lay the weight of something beyond mortal comprehension.

His skin had taken on a flawless, almost porcelain-like quality, smooth yet undeniably durable. It radiated an unnatural perfection, as if he had transcended the very concept of a normal body.

As if answering the transformation of its master, his attire had also changed. Gone were the simple clothes he once wore—in their place was an exquisite black and crimson ensemble, woven from the very essence of his magic.

A high-collared, form-fitting black coat, its fabric shifting like liquid darkness, lined with intricate crimson patterns resembling arcane runes. It had a regal yet ominous presence, the ends flowing slightly as if alive with his magic.

Beneath, a dark tunic with silver embroidery, fitting seamlessly to his new physique. The craftsmanship was beyond mortal means, reinforcing his newfound status.

Black gloves, embedded with subtle red markings that pulsed whenever he channeled his power. They felt as though they were an extension of his very soul, crafted to withstand his own immense energy.

A flowing obsidian cape, trimmed in silver and crimson, moving as if possessed by an unseen force, responding to his very mood.

His boots, armored yet elegant, clicked softly against the stone floor as he stood. They, too, bore faint arcane symbols, ensuring he could tread through dimensions themselves without resistance.

Everything about his appearance had changed—not just in form, but in essence. He was no longer just Arion.

He had ascended.

He looked at his reflection in a polished surface nearby, his crimson eyes narrowing slightly as he studied himself.

A smirk played at his lips.

"Now this… this is more fitting."

In the depths of the Underworld, where malevolent energies twisted and coiled like living entities, Noir sat upon his throne, fingers tapping rhythmically against the armrest. His golden eyes gleamed as he suddenly felt it—a tremendous shift in power.

It was subtle yet undeniable, a presence awakening, one that sent ripples through existence itself. He knew exactly who it was.

A wicked grin spread across his lips.

"Fufu… So, you've finally ascended, Arion."

Even from his domain, Noir could feel the immense energy pulsing from his former disciple. The once-nameless Archdemon he had trained had now become something far greater—a Demon Lord. And not just any Demon Lord… one powerful enough to shake the foundations of the world.

Noir chuckled, leaning forward slightly. This was rare—to witness the birth of such an extraordinary being.

Then, without warning—

Ding!

A deep, resounding voice echoed in his mind.

"Due to your connection with the individual Arion, the system has determined you worthy of a gift."

A surge of dark energy coiled around him like mist, wrapping him in its embrace as the announcement continued.

"New Unique Skill Acquired: "Shadow Covenant"—Allows the wielder to forge binding contracts through the abyss, enhancing the loyalty and strength of those who serve under them."

A rush of knowledge flooded his mind. This was not just an ordinary skill—it was a tool of absolute dominance. With this, he could form contracts with unparalleled authority, ensuring unbreakable bonds of servitude.

Noir let out a pleased chuckle, his eyes glimmering with amusement.

"How delightful… Such a promising child, and he's already bringing me gifts."

He leaned back, a satisfied smirk gracing his face.

"Arion, you continue to entertain me. I look forward to what comes next."

Arion, now fully immersed in his newfound power, turned to look at Veldora, who was still reeling from the surge of strength granted by his Ultimate Skill: Faust, Lord of Investigation. The mighty Storm Dragon was practically vibrating with excitement, his golden eyes gleaming as he reveled in his power.

Letting out his signature three-stage laugh, he roared,

"Wahahaha! Hahaha! Mwahaha! I, the great Veldora, have ascended to new heights! Even the heavens will tremble before my might!"

Arion smirked, amused by his antics.

Still, a thought crossed his mind.

"By the way, Veldora… can you take on a human form?"

The dragon's laughter abruptly stopped.

Silence.

A strange, almost awkward stillness filled the air.

Veldora's massive golden eyes blinked as his expression stiffened. His towering body shifted slightly, his claws fidgeting as he rolled his massive fingers against each other.

Then, he turned away, his massive wings twitching in what could only be embarrassment.

"…Ahem… W-Well…"

Arion raised an eyebrow, already suspecting the answer.

Veldora grumbled, his deep voice unusually hesitant.

"I can do many things! I can summon storms, I can destroy mountains,Wahaha!"

"…But?" Arion pressed, crossing his arms.

Veldora let out a low, reluctant growl, his tail flicking behind him.

"…But I don't have a human form."

He said it so quietly, it was almost a whisper—if a dragon could whisper.

Arion's smirk widened.

"Really?"

Veldora huffed, looking away.

"Hmph! It's not like I need one! My dragon form is already perfection! Why would I ever require something so trivial?"

Even as he said that, Arion could see it—the slight frustration in his eyes, the lingering sense of missing something.

Veldora wasn't just proud—he was a little… envious.

Arion thought for a moment, then, without a change in expression, he called out internally:

"Pandoria, is there a way to grant Veldora a human form?"

The voice of Pandoria, the Abyssal Architect, whispered into his mind, her tone cool and calculating.

"Multiple methods detected. Calculating optimal solution…"

Veldora, completely oblivious, continued to grumble to himself, flicking his tail and muttering something about "stupid human forms" and "who even needs one anyway?"

Then, Pandoria spoke again.

"Solution found. There is a way to grant Veldora a human body. Would you like to proceed?"

Arion's crimson eyes shimmered with intrigue as he leaned back slightly, a smirk forming at the corner of his lips.

"Oh? Tell me more."

"Solution found. The individual Veldora must transfer his essence into a body double that you create. Once inside, he will have full control and can reshape the vessel to his liking."

Arion considered this, then turned his gaze toward the Storm Dragon.

"Veldora, what if I told you there's a way for you to have a human body?"

Veldora's golden eyes lit up, excitement flashing across his face, though he quickly folded his arms, attempting to feign indifference.

"Hmph! Well, of course, there is! I am Veldora! If I willed it, I could easily do such a thing."

Arion raised an eyebrow.

"Really? Then how come you haven't done it?"

Veldora flinched. His tail flicked, and his massive wings twitched slightly.

"I... I simply haven't felt like doing it! I enjoy my true form. It is a work of art, a symbol of my greatness! Wahaha!"

Arion sighed.

"Alright, alright. But what if I create a body for you? One that you can enter and reshape however you want?"

Veldora's pupils dilated, his interest immediately piqued.

"Wait… you can do that?"

Arion smirked.

"Of course. You just have to move your essence—your consciousness, soul, and mind—into the body I create. Once inside, you should be able to mold it to your preference."

Veldora stared, his massive body motionless for a moment. Then—

"Wahahaha! That's simple! Child's play! I, the mighty Veldora, can do that with my eyes closed!"

Arion chuckled.

"Then let's begin."

Arion raised a hand, magicules swirling as he began constructing a body for Veldora. The air trembled as dark energy coalesced, forming a humanoid shell—featureless but sturdy, built to house the powerful Storm Dragon's soul.

Veldora nodded to himself, stepping forward with a smug expression.

"Hmph! Watch closely, Arion! This is nothing for someone of my stature!"

He closed his eyes, summoning his power to transfer his essence into the vessel.

The air vibrated. Magicules crackled.

Veldora's massive form shuddered as a golden glow surrounded him, his spirit attempting to separate from his draconic body.

Then—

BOOM!

The magic shattered, the vessel collapsing into dust.

Veldora's golden eyes snapped open. He blinked.

Arion sighed, shaking his head.

"I thought you said this was child's play?"

Veldora coughed loudly, scratching his snout.

"Ahem! That was merely a warm-up! I was testing the flow of magicules, you see! It's all part of the process! Wahaha!"

Arion crossed his arms.

"Right. Let's try again."

Veldora tried again.

And again.

And again.

Each time, something went wrong.

Once, his essence scattered, unable to focus.

Another time, the vessel overloaded, exploding into particles.

Then, he almost got it—only for the body to turn into a slimy blob instead of a humanoid form.

By the time night fell, Veldora was growling in frustration, his tail whipping against the ground in irritation.

"What is this nonsense?! Why is my perfect self unable to enter such a simple vessel?!"

Arion, sitting nearby with his arms behind his head, smirked.

"Maybe it's not as easy as you thought?"

Veldora gritted his teeth, fuming.

"Grrr… this is unacceptable! I refuse to be bested by mere magicules! Tomorrow, I shall perfect this! Just you wait! Wahaha!"

Arion rolled his eyes.

"Sure, sure. Get some rest, oh mighty Veldora. You'll need it."

At dawn, Veldora tried once more.

This time, he calmed himself, listening carefully to Arion's guidance.

Arion spoke patiently, explaining the finer details of soul transference, guiding Veldora step by step.

Then—

Veldora focused.

His golden body glowed with raw power as he willed his soul, consciousness, and mind into the vessel. The energy swirled, flowing seamlessly into the humanoid shell.

A tremor shook the earth.

Then—a bright, radiant light erupted.

The huge draconic form of Veldora began shrinking, his enormous wings folding inward, his towering body compressing smaller and smaller.

His mighty claws retracted, turning into elegant fingers.

His golden scales morphed into skin.

His massive tail faded, and his form slimmed down, becoming… human.

When the light faded, standing in place of the Storm Dragon was—

A tall, well-built man, 6'2 in height, with blonde hair cascading to his shoulders. His golden eyes gleamed, sharp and powerful, brimming with draconic might. His body was sculpted, radiating raw strength, yet retaining a regal, untamed aura—a being of power now wrapped in a human frame.

A deep silence filled the air.

Then—

Veldora lifted his hand, flexing his fingers.

He blinked.

Then he grinned.

"Wahahaha! I did it! I—THE MIGHTY VELDORA—HAVE ASCENDED!"

Arion smirked.

"Took you long enough."

Veldora crossed his arms, his human body exuding pure confidence.

"Hmph! This was but a mere test of patience! Behold, my new form! Magnificent, is it not?!"

Arion studied him, nodding.

"Not bad. Now, let's see if you can actually use it properly."

Veldora grinned, cracking his knuckles.

"Wahaha! Watch closely, Arion! For I, the great Veldora, shall now explore the world in this magnificent new form!"

Arion chuckled.

This was going to be interesting.