Immediately following, a black, malevolent Aura surged around the Lord-Level Experimental Subject, like a fiercely burning and wildly churning black flame. This Aura was so dense it seemed to solidify, constantly rolling and twisting.

It was mixed with a nauseating stench of decay and a pungent smell of blood. The stench was like the odor emanating from countless corpses piled up over many years.

And the blood was like the Aura of a battlefield that had just undergone a brutal massacre. The two combined to form a terrifying smell that could instantly cramp one's stomach and induce vomiting, as if it emanated from the darkest corner of Hell's abyss, directly assaulting everyone's olfactory nerves.

Accompanied by a deafening roar, the volume of the roar was so immense it seemed capable of collapsing the entire Underground Base.

The sound waves, like solidified power, continuously echoed through the passage, wave after wave, making everyone's ears buzz as if countless bees were frantically flying around their ears.

This roar contained endless rage and ferocity, making it seem as if one could see an ancient beast, thoroughly enraged, unleashing its fury with an Aura of destruction, disregarding everything.

It moved all four limbs simultaneously, its muscles bulging, each muscle seemingly containing infinite power, propelling its massive body like a black raging tide, charging towards the Ninth-Order Mingling Demon.

Its speed was beyond the limits of human imagination, creating an intensely strong gust of wind.

The surrounding air seemed to be furiously squeezed by an invisible and incredibly massive hand, emitting a dull 'humming' sound, like the desperate wail of an overloaded machine operating at its limit, on the verge of breaking down.

This gust of wind rapidly spread out from the experimental subject, forming an invisible yet extremely oppressive wall of Qi.

Wherever the Qi wall passed, the long-accumulated dust on the ground was swept high, and those dust particles, as if by magic, instantly formed small dust storms.

These dust storms raged within the passage, like small tornadoes, making visibility extremely blurry. Only a hazy gray scene could be seen, making it almost impossible to distinguish surrounding objects.

The lights in the passage also flickered erratically due to the impact of this powerful force, sometimes bright as day, with intense light stinging the eyes;

At other times, it was so dim that almost nothing could be seen, the light bulbs shaking violently in their sockets, the filaments flickering on and off as if they could extinguish at any moment, the entire scene akin to being in the most terrifying movie, full of the unknown and danger.

The Ninth-Order Mingling Demon, however, showed no fear of this terrifying scene or its powerful opponent.

A resolute light gleamed in its massive compound eyes, like the brightest star in the night sky, luminous and full of power, its gaze revealing an eager desire for this battle and a strong belief in victory.

Its carapace, under the dim and flickering light, shimmered with a cold metallic luster, like an indestructible armor, each segment tightly connected, as if a meticulously crafted war fortress.

Upon closer inspection, there were faint traces of battle, either tiny scratches or worn marks. These traces seemed to silently recount the countless brutal battles it had endured, each a struggle of life and death, yet it had never retreated.

Facing the Lord-Level Experimental Subject's overwhelming attack, it not only showed no intention of retreating but instead actively charged forward.

It slightly bent its legs, its leg muscles instantly tensing, each muscle as hard as steel, accumulating all its strength.

Immediately after, it leaped fiercely, its entire body like an arrow released from a bowstring, flying towards the experimental subject with an unstoppable Aura.

Mid-air, the blades on its arms instantly extended, glinting with a cold light under the faint illumination, like a scythe wielded by the Grim Reaper, emitting a deadly Aura.

The edges of the blades shimmered with a cold gleam, as if a mere flick could easily tear through the air, making the surrounding space seem to tremble.

The two instantly collided, producing an earth-shattering roar, a sound like the collision of two planets, powerful sound waves spreading outwards from the two, as if to shatter the entire world.

This impact force was like the explosion of a high-energy missile, releasing unparalleled energy.

Centered on the two, the surrounding metal walls instantly developed countless cracks under the impact of this force.

These cracks spread rapidly like a spider web, the metal emitting a 'creaking' and 'groaning' sound under immense pressure, as if groaning in pain, enduring unimaginable torment.

The ground also began to shake violently, and cracks rapidly extended outwards from beneath their feet, growing wider and deeper.

In some places, the ground even began to collapse, rocks falling, raising a sky full of dust, like a small earthquake.

The instruments and equipment in the passage, under the rampage of this powerful force, exploded one after another, sparks flying.

The fragments scattered like bullets, hitting the surrounding walls and ground, making 'clinking' and 'clanking' sounds, like a chaotic metal symphony.

The Lord-Level Experimental Subject and the Ninth-Order Mingling Demon moved past each other in the aftermath of the impact.

The experimental subject, relying on its massive size and brute strength, launched a heavy punch towards the Mingling Devil, the punch wind howling as if it could ignite the air itself.

The air was compressed by this punch, forming a visible circular Qi wave that spread outwards from the fist, and wherever it went, terrifying Qi explosions continuously roared.

The Mingling Devil's eyes narrowed, the light in its massive compound eyes instantly becoming as sharp as an eagle's. With agile movements, it dodged sideways, its actions as fast as lightning.

The fist grazed its carapace, creating a scorching airflow that slightly warped the air on the Mingling Devil's carapace surface.

Before the experimental subject could retract its fist, the blades on the Mingling Devil's arms swung fiercely, a cold light flashing, seemingly leaving two icy trails in the air.

The blades directly cut two deep wounds on the experimental subject's arm, and black blood surged out from the wounds like water jets from a high-pressure hose.

It splattered onto the surrounding ground and walls, making 'thudding' sounds, and the black bloodstains spread across the metal surface, emitting a nauseating odor.