Solo Cultivating in Superhero Academy
Chapter 138: Cube

Chapter 138: Cube

The passage narrowed into another corridor choked with rising smoke and exposed electrical veins running through cracked walls.

The clatter of metal echoed ahead—more enemies.

Elius didn’t stop.

His swords were already spinning, reflecting the flickering lights. Keith jogged behind, panting but keeping pace. His steps faltered now and then, but he said nothing.

They turned the corner and were instantly met by four flaming centipede drones barreling toward them, leaving molten trails in their wake.

Their red-hot bodies clicked as hundreds of limbs scrambled forward.

Elius flicked two fingers.

FWOOOM!

Two swords lunged forward like lightning bolts, skewering the first pair. The other two bots swerved, releasing a barrage of napalm shots.

Keith dove and rolled. "They’re getting faster!"

"Or you’re getting slower," Elius murmured.

His remaining swords spun in midair and slashed down.

KRZZZT!

The last two drones were cleaved in synchronized arcs, scattering sparks and metal debris.

Keith exhaled and stood up, brushing the soot from his arms.

Then—

Ding!

---

[Fragment of Martial Skill found!]

Martial Skill: Unknown

Type: Thunder type.

Fragments: 4 / 5.

Effect: Fragment only.

Collect remaining pieces to unlock full skill.

---

Another message only Elius could see.

He narrowed his eyes slightly.

The Thunder-type skill was almost complete now. It seems he just needs a little push to find the final fragment.

What skill would it be? Elius was excited.

His pace quickened, his senses sharp, swords circling him like hunting hawks.

Keith noticed the change in tempo.

He opened his mouth to ask something—but stopped. He didn’t understand what his brother kept collecting after every kill.

Whatever it was, it made him stronger. But Elius never told him, not even once.

And Keith knew better than to ask again.

Soon, they cleared another hallway filled with scorched synthetic corpses and scattered plating.

One last bot sputtered to life, crawling weakly toward the duo, its arm sparking violently. Before Keith could aim, Elius flicked his hand.

A sword darted forward and silenced the bot with a clean pierce to the core.

Ding!

---

[Martial Skill Unlocked!]

Skill Name: Thunder Steps – Lv.1

Type: Thunder

Effect: Temporarily boosts user’s speed by 20% with a burst of lightning along the soles. Each step leaves behind a brief afterimage. Cooldown: 10 seconds.

---

Elius looked at the floating text. His eyes narrowed in mild disappointment.

"...Hmph."

He crossed his arms as the swords circled lazily behind him.

"Ghost Step is faster," he muttered. "More silent. Doesn’t make sparks."

Thunder Steps had its merit, but the noise, the flash—it wasn’t suitable for stealth or precision. He preferred being unseen and unheard.

This?

It was for show-offs.

It’s fucking weak and useless.

He sighed and dismissed the screen.

Unfortunately, the system didn’t allow him to delete or give it away. It was now bound.

Which makes him a little more disappointed.

Elius would have a glint in his eyes.

That Zhark, the system made something useless for Elius, he is now planning to punish him.

"Just let it be," he muttered.

Keith blinked. "You say something?"

"No. Move."

They continued.

The next set of enemies was waiting: spidery constructs, smaller and more agile, scuttling across the walls and ceiling. One leapt straight at Keith’s face.

THUNK!

A sword speared it mid-air.

Keith flinched but nodded gratefully.

Soon, after clearing the next three rooms, they encountered another wave, and this time—

Ding!

---

[Fragment of Martial Skill found!]

Martial Skill: Unknown

Type: Normal type.

Fragments: 3 / 5.

Effect: Fragment only.

Collect remaining pieces to unlock full skill.

---

Elius raised a brow. "Normal type?"

Curiosity flickered, but not much expectation. Still, he pressed on.

More battles followed. Keith tried to keep up, landing hits when he could, providing backup where possible. He was improving, but nowhere near the level Elius demanded.

Another surge of robotic beasts poured into the chamber.

Elius danced between them, his swords weaving deadly threads in the air. One beast roared—an abomination with jet thrusters for legs and a hydraulic blade-arm.

It lunged.

Elius’s clone formed beside him—a flickering, half-transparent image that took the hit instead.

BOOM!

The clone shattered, but not before giving Elius the opening. He swapped mid-air, flipping behind the beast and ramming a sword straight through its head.

Ding!

---

[Fragment of Martial Skill found!]

Martial Skill: Unknown

Type: Normal type.

Fragments: 4 / 5.

Effect: Fragment only.

Collect remaining pieces to unlock full skill.

---

And then—minutes later, after a battle with a flame golem infused with reactor cores—

Ding!

---

[Fragment of Martial Skill found!]

Martial Skill: Unknown

Type: Normal type.

Fragments: 5 / 5.

Effect: Full skill unlocked.

New Martial Skill Learned: Aura Illusion – Lv.1

Effect: Creates a false spiritual or Esper aura to mislead detection and tracking techniques. Useless against high-tier perception abilities or those using spiritual sense.

---

Elius barely glanced at it.

"Another trash?"

He didn’t even bother hiding his disappointment this time. "I can already mask my aura through spiritual compression. Why would I need this clown trick? Is this all the system can give me? Useless items?"

He sighed and shook his head.

Another wasted slot. It seems he cannot have it all.

But he pressed forward. Because he wasn’t done yet.

He still needed one more Martial Skill.

And this next one—he planned to take it even though it wasn’t meant for him.

They advanced through another long hallway. The lights flickered, casting distorted shadows on the wall. Their steps echoed.

Then—

CLANG!

A small cube slipped from Keith’s side pouch and hit the ground, spinning slightly.

Elius turned at once.

"...You still have that?" he asked.

Keith flinched. "I—I thought I dropped it before... but I guess it stayed in my pack somehow."

His hand hovered over it uncertainly. The cube pulsed faintly, emitting a soft red glow.

Elius’s eyes narrowed. "You shouldn’t let that thing roll around like a marble. Especially in an F-rank Dungeon."

Keith hesitated. "Should I leave it here? Might be cursed..."

"No," Elius said firmly. "That’s a dangerous object. If a Dungeon Beast so much as licked it, the whole structure might collapse. Take it. Secure it tightly. Do not drop it again."

Keith nodded, eyes wide. He reached down and carefully pocketed the cube once more.

"...Sorry."

Elius didn’t respond. He was already turning forward again.

But as they walked deeper—

A glint passed through his eyes.

He didn’t look at Keith. Just kept walking.

"So... he still has it. And he didn’t tell me. Did he plan to keep it hidden? Or use it? Interesting."

He said nothing aloud.

Just mumbled to himself under his breath: "Seems my brother... wants to betray me."

He didn’t act. Not yet.

But the seed of suspicion had taken root.

Meanwhile, a few steps behind—

Keith walked with his head slightly bowed, but a sharp glimmer danced in his gaze.

"...Fortunately, he didn’t seem to notice."

He tightened his grip on the cube in his pouch and kept walking.

Both brothers, side by side. Silent. Focused. But thinking very different thoughts.

Neither trusted the other completely now.

The dungeon trembled slightly as they entered its deepest part—a tunnel leading into an abyss shrouded in electric fog and crimson steam.

Metal roared in the distance. Something massive was waiting.

Elius cracked his knuckles.

Keith tightened his gloves.

And together, they stepped into the heart of the fire.