Tick… tick… tick…
The sharp sound of water droplets echoed clearly in the silent alley.
A thick, pungent stench of blood hung heavy in the air. Crimson liquid spread rapidly across the ground, staining the darkness with its sticky glow, turning the alley into a scene straight out of hell.
The red-haired youth and the brown-haired woman had yet to recover from the sudden carnage. Their eyes were wide and glassy, frozen on the horrific sight before them.
Chomp… chomp… chomp…
The grotesque maw of flesh protruding from Mammon's arm chewed noisily, while Mammon himself stared at what remained of the yellow-haired drunk's mangled body with a detached expression.
"…The taste is awful."
Mammon frowned slightly and willed the flesh-mouth to spit the body back onto the ground in disgust. Even though he had become a demon, and demons were meant to feed on human flesh and blood, something within him recoiled. Whether it was psychological or simply because the man had been nothing but filth, Mammon despised his flesh.
At that moment, the red-haired drunk and the brown-haired woman snapped back to their senses. Terror seized them both.
"Y-You… you're a monster!"
The red-haired youth's entire body shook, his finger trembling as he pointed at Mammon. The haze of alcohol vanished instantly, replaced by pure fear.
Yes—humans had evolved in strange ways in this world. But nothing like this. Nothing this inhuman. This could only be a monster.
The woman, already pale, collapsed under the weight of her own terror. Her mind screamed at her to run, but her body refused to obey.
"Monster? I'm not a monster."
Mammon lowered his gaze, crimson eyes glinting as the fleshy appendage lashed forward.
Crack!
A scream tore from the red-haired youth as the monstrous arm tore him apart. The sound of bones snapping and blood splattering filled the alley, forcing the woman to crumple to the ground completely, paralyzed by fear.
Step… step…
The sound of Mammon's quiet footsteps rang sharp in the silence.
"N-no… please… don't…"
The brown-haired woman raised her tear-streaked face. The pale boy was closing in, scarlet eyes cold and unyielding. Her survival instincts forced the words from her lips, broken and weak.
Mammon crouched in front of her, his gaze piercing."I'll ask you one thing."
The woman shook uncontrollably as his scarlet pupils bore into her.
"Do I look half-dead to you?"
Her head jerked side to side in frantic denial, but the tears streaming down her face betrayed her terror.
Mammon's lips curled into a shadowed smile. He raised his hand, an index finger extended. The nail lengthened into a sharp, gleaming claw.
"My blood… can make people evolve."
He thrust the claw forward. Shhk! It pierced her forehead effortlessly. The woman screamed, her features contorting grotesquely in pain.
"But if I give you too much blood…" Mammon withdrew his hand and rose to his feet, watching coldly as the transformation began. "Your cells collapse. They can't withstand the speed of change."
The woman writhed, her body convulsing as purple lines spread like veins of poison across her skin. Her form swelled and warped, expanding grotesquely.
Boom!
With a wet explosion, her body finally gave out—collapsing into a pool of steaming, writhing flesh.
Mammon merely looked on. His expression didn't change. To him, killing these three was no more significant than crushing three filthy rats.
Nor did he worry about consequences.
This was a world where the strong preyed on the weak, where sin and evil rotted through every corner of society. Wiping out trash like this carried no weight on his conscience.
"…Hm?"
Just as he was about to leave, something caught his eye. He turned back toward the remains of the woman.
Squeak! Squeak!
Several sewer rats scurried into the alley, drawn by the stench of blood. They swarmed over the remains, gnawing greedily at the steaming flesh.
Normally, the blood-tainted meat would soon disintegrate under its own instability. But before that could happen, the rats devoured it.
Mammon's crimson eyes narrowed."Muzan's blood… not only works on humans?"
In Demon Slayer, only humans could be transformed into demons. But here… in this world… what if Muzan's blood could turn other creatures as well?
That thought sent a flicker of intrigue through Mammon's otherwise icy gaze.
This wasn't his past life. This world had changed ever since dimensional rifts had torn open, flooding it with otherworldly creatures. Humanity was no longer the sole master of the land.
And now…
The rats feasted. The blood called to them, ensnaring them like a fatal lure.
One rat convulsed violently, twitching and seizing as blood vessels burst across its eyes. Then, before Mammon's gaze, its body began to swell. Muscles twisted, bones cracked, and in the span of seconds, the sewer rat grew to the size of a hyena.
Mammon's lips curved ever so slightly."…Seems there's some effect, after all."