By now, the massive, raging vortex of steel generated by the Flying Demon Keys had fully materialized, producing a terrifying gravitational pull. While a Contractor might just manage to stand or move within it, launching an attack was utterly impossible. Standing within the terrifying storm formed by the Flying Demon Keys, she spread her arms wide, tilted her head back, and then produced a vial emitting a faint, dark-gold luminescence: “This powerful potion cost a full ten Honor Points plus ten thousand Universal Credits to acquire! Furthermore, one must possess the rank of Colonel in the Nightmare Imprint to even purchase it! Drinking this will instantly restore my health to maximum, and it will also grant me a temporary shield around my person! The shield's health is equal to three times my maximum health, meaning I am now at six hundred health points! Can you fight me? Do you dare fight me? Now you have two desperate choices: either be torn to shreds by the furious iron vortex formed by the Flying Keys, or let me find you once I escape and flay the flesh from your bones piece by piece with my Metal Shards!”

Fang Senyan tore off his outer garment in a single motion, revealing a sturdy, muscular upper body. Explosive power seemed contained within every defined muscle. Though covered in scars, Fang Senyan, standing with arms spread across the doorway, resembled a wounded, savage beast—even fiercer, more frenzied, and bloodthirsty. He licked a streak of blood running down his face; the metallic taste ignited his eyes with a searing, arrogant, and defiant glare.

“I choose the third option, Metal Mentor! I choose to stay right here and watch you get torn apart alive by that savage iron vortex! I will live, and you will die!!!!”

Metal Mentor Flora let out a burst of mocking laughter, so intense it seemed she might weep. After downing the potion, a faint dark-gold light emanated from her mouth and throat, even making her abdomen somewhat translucent, as if she had swallowed a miniature sun. This dark-gold radiance then spread across her entire body before coalescing into a shimmering, almost liquid-surfaced shield around her.

At this moment, all the Flying Demon Keys were completely frenzied, forming an immense, terrifying black vortex. Sparks erupted continuously from the stone walls and floor of the entire hall as they collided, the screeching friction threatening to rupture eardrums. Death was vigorously churning everything.

Fang Senyan said nothing more. A slight smirk played on his lips as he simply extended his right hand, palm facing the ceiling, and pointed his middle finger directly at the Metal Mentor, beckoning with a wicked curl—the exact gesture he used when flirting with waitresses in bars during his days running cargo ships.

At this razor’s edge between life and death!

The Metal Mentor’s fists clenched tight; she had no more words left. Her venomous gaze was locked onto Fang Senyan’s body. She had to witness this man being violently shredded, minced, and executed by the raging iron vortex to satisfy even a fraction of the hatred churning in her soul.

At this point, every location in the hall was suffering massive, indiscriminate damage, attacked simultaneously every second by two mad Flying Demon Keys!

Because the Flying Demon Keys possessed the ability to ignore all defensive effects—a priority even higher than the terrifying 'Domain Priority' special effect—and inflicted damage at an extremely rapid rate, their damage output under the current world difficulty had to be constrained, usually rarely exceeding ten points per hit. Based on Fang Senyan’s calculations, the average damage per key was about 6 points.

Fang Senyan had previously been hit by the raging steel vortex triggered by Deco and Phil, so his remaining health was only around 280 points. However, he was protected by the powerful Toughness talent, which reduced the damage he took to only two points per second. Conversely, despite the Metal Mentor having six hundred health points, she had no way to mitigate the damage from the wildly circling Flying Demon Keys, suffering at least 12 points of damage per second!

This meant that, even without accounting for any automatic health regeneration on either side, the Metal Mentor could last at most fifty seconds in the savage steel vortex, whereas Fang Senyan could hold out for two and a half minutes! Fang Senyan had calculated this difference perfectly, which explained his profound composure.

After enduring the raging steel vortex for about thirty seconds, the Metal Mentor began to sense something was wrong. Her six hundred health points had already been reduced by more than half, leaving her only 240. Under normal circumstances, even with instant 100% health recovery medicine, Fang Senyan should have been precariously close to defeat by now, rather than maintaining that composed, faintly mocking demeanor as he stood steadfastly before that mysterious, ancient stone door.

Survival instinct drove the Metal Mentor to move forward with immense difficulty within the frenzied metal storm, her hand tentatively reaching out to push Fang Senyan away. Fang Senyan, meanwhile, remained unmoving in the raging steel vortex that resembled a typhoon, his arms crossed over his chest, watching her with cold indifference. If this woman, as an elemental Contractor, somehow possessed greater raw strength than him, Fang Senyan would have nothing more to say.

The savage storm roared past, carrying whispers of death and brutal stripping. Fang Senyan met the Metal Mentor’s gaze coldly. Her dark-gold shield had shattered, and grievous, bleeding wounds were already appearing on her body, yet she seemed oblivious. Her emerald eyes, blazing with resentment, stared fixedly at Fang Senyan before she suddenly screamed in fury:

“I know it! You must naturally possess a defensive talent (Tactical Core Tank)! You must!”

Saying this, the Metal Mentor reached out towards Fang Senyan’s face, as if trying to touch the deepest secret of his soul. But at that moment, the raging steel vortex grew even more violent and frenzied, tinged with a faint crimson hue. Fang Senyan could clearly see the arm the Metal Mentor extended toward him: the armor was rapidly shredded and peeled away in layers, followed by flesh and muscle, leaving only bare, white bone. Finally, even the bone fingers were instantly sliced into scattered ash-like debris, swept away by the wind!

Witnessing such a gruesome scene, Fang Senyan sighed, an indescribable, faint melancholy rising in his heart. He lowered his gaze and said softly, “Amen.”

With a great effort, he pulled shut the heavy, ancient, and mysterious stone door, sealing the raging iron vortex behind the thick stone barrier. His ears suddenly found quietude. He sank down against the door, retrieved a bottle of pre-prepared water from the Nightmare Imprint, took a drink, licked his lips, rested his head against the stone, closed his eyes, and began to rest.

Though his body was at rest, Fang Senyan’s thoughts did not cease.

Despite the Metal Mentor having effectively died by his hand, Fang Senyan still had to state firmly that she was the strongest Contractor he had encountered thus far; even the mysterious woman “Zi” he met in the Caribbean world was definitely less powerful than the Metal Mentor.

And Nu’s strength was equally terrifying; the massive, thick-plated Stegosaurus he summoned alone possessed the power to contend with a legendary monster like a Mountain Giant in a direct confrontation!

If these two had not been utterly determined to discard Contractors focused on melee defense, treating them purely as cannon fodder, Fang Senyan would not have minded pursuing further cooperation with them.

It was simply that the Metal Mentor and Nu, aside from each other, trusted absolutely no one else. They were like moths drawn to a flame, ceaselessly pursuing their own ideals and beliefs while viewing everyone else as a tool to be exploited.

A person like Fang Senyan, naturally, refused to be merely a tool—especially one that could be sacrificed at any moment.

Therefore, the conflict between them was irreconcilable; it was a zero-sum game where one had to die for the other to live, akin to the profound chasm separating the proletariat and the capitalist class. Thus, in that mysterious, thick-walled stone chamber, it was destined that only one side would walk out alive.

“A naturally gifted Tactical Core Tank, huh? That sounds rather impressive. I rather like that title.”

Fang Senyan splashed cold water on his face and shook his head, rising to his feet. He was now alone, and before this defensive line known as the Metal Digestive System, he needed to be doubly cautious. Strictly speaking, this place had only been constructed five thousand years ago when those Goblins refitted Gringotts—though the word “only” was certainly an understatement.

Before him stretched a long passageway, at least six meters high and seven to eight meters wide. The floor and walls were pieced together from massive stones, each block measuring at least five meters square. Despite the ravages of time, the area remained solemn and imposing, adorned with exquisite carvings and patterns along the walls. On both sides of the corridor, approximately every six meters, stood lifelike stone sculptures three meters tall, depicting either Goblins or Dwarves holding torches in various attitudes. As Fang Senyan cautiously passed by, the torches they held would sequentially ignite, only to extinguish automatically when he moved away.