Deeper within the shadowy recesses of the Chamber of Secrets, a hidden alcove lay submerged in impenetrable darkness. This was Avery's innermost sanctum, warded by the most formidable curses and protections.
With a complicated wave of his wand, the murky gloom of the alcove dissolved to reveal its unhallowed contents. Avery's eyes gleamed with satisfaction as he took in the horrifying collection of artifacts, each steeped in vileness and reeking of dark magic.
In the center, proudly displayed upon an obsidian pedestal, was the twisted trunk of Voldemort's iconic snake familiar Nagini, hideously transfigured and preserved as a grisly keepsake. Avery reveled in the vile presence as he slowly circled the pedestal.
"Soon, my repugnant pet," he murmured, caressing the serpentine body with perverse reverence. "Your noble master's power shall be reconstituted through me."
From beneath his robes, Avery carefully extracted a small, black silk pouch, weighing it in his palm. He knew the priceless contents within - a few precious shards of bone, harvested from the very ashes and earthly remains of Voldemort that fateful night in the Forbidden Forest.
These unholy Remnants were some of the only fragments of the Dark Lord's mortal shell that remained. Avery had been gifted them by his father upon being initiated into their dark legacy - the sole son sired by Rodolphus Lestrange, born of a random female Death Eater.
Which also made him the reviled complicated family member of Delphi. While Delphi clung to pathetic delusions of warping time to resurrect her father, Avery had far grander, more realistic ambitions.
He would seize control of magic so dark and destructive, he could personally become the harbinger of a new Wizarding apocalypse. A scouring purge to cleanse the magical realm so he could refound it under Voldemort's twisted vision of supremacy once and for all.
All he required was a wand imbued with the focused totality of that ancient, abominable magic. A wand that could only be forged by harnessing his unique, hereditary link to Voldemort's essence.
"The ultimate wand of darkness is nearly within my grasp" Avery intoned, clutching the bone shards reverentially. "Father...your master shall deliver unto this world"
In the flickering torchlight, his obsidian eyes glinted with dreadful, soul-hardened determination. The hour of the new Dark Lord's ascent was nigh.
Avery's mind drifted back, years before he attended Hogwarts, to the dreary confines of his childhood home. If one could even call it that - it was more an ill-omened keep, situated in the barren moors of the northernmost Scottish highlands. A place as dismal and haunted as its inhabitants.
He remembered skittering down the gloomy corridors, afraid to make any sound lest he incur the wrath of his towering, severe-looking mother. Griselda Avery cut an imposing figure despite her gaunt frame, her raven hair always drawn back in a harsh bun and her hollow cheeks chiseled into planes of cold disdain.
To the unwitting eye, she was a reclusive pureblood widow. But Avery knew better even from a tender age. He recognized the darkness that cloaked his mother like a malignant shroud, felt the hum of arcane magic lingering in the shadowy recesses of their decaying manor. This woman was far more than she appeared. On his eighth birthday, as young Malcolm peered at the meager offering of a stale crumpet meant to pass for a "treat", Griselda had rasped out the first words alluding to the truth of his unnatural birth.
"Son..." Her tone made the hairs prickle on the back of his neck, cold and devoid of any semblance of nurturing warmth. "You must know...you were borne of the noblest of causes. Conceived to one day avenge the greatest wizard who ever walked among us."
She ran a bony finger along the underside of his quivering chin, her black eyes boring into his.
"Delphini is the daughter of the Dark Lord and his most loyal Death Eater...her husband, Rodolphus is your father...I know you can't understand that now...but you are going to understand..."
The young boy's eyes had widened in shock and a hint of fear at this revelation. But Griselda's steely grasp grew vice-like as she forced his face up.
"Do not be afraid of your destiny, boy. You were bred for greatness unparalleled when all others forsook their duty."
She sneered as she spat out the dreaded name...
"Potter..."
Griselda rose suddenly, a manic light flickering behind her eyes as she towered over her cowering son.
"It will be you, my son... You shall raise an unholy sword of wrath to strike down Harry Potter and his spawn once and for all!"
Malcolm experienced visions of the domination, chaos, and destruction. And now, here in the hallowed bowels of Slytherin's Den, those visions edged closer towards their apocalyptic culmination. Soon, Malcolm thought with a cruel smile...soon.
Deep in intense meditation, channeling his evil energies, Avery was startled by the sudden clatter of stone ahead of him. His eyes flew open as the massive serpentine door to the Chamber shuddered and began sliding apart.
"What?" he snarled, whipping around with his wand raised. "Who dares interrupt my-"
The words died in his throat as two figures strode purposefully into the sinister chamber. At their lead was none other than Harry Potter himself, emerald eyes blazing with determination behind his glasses. And at his side, wand extended...was his miserable son Albus.
"Avery!" Harry barked, his wand sweeping to cover the shocked young Slytherin. "We know what you've been up to skulking down here. This ends now!" Albus too had his wand trained on Avery, though his expression held more sadness than anger.
"Malcolm...whatever path you think you're being driven down, you have to stop this madness," he urged. "My father and I, we know your true-"
"You know nothing, you contemptible half-breed!" Avery spat, his surprise melting into vehement rage.
With a savage slash of his wand, a lurching cone of pitch darkness exploded outwards, swallowing Harry and Albus in impenetrable shadows. They cried out, temporarily blinded and defenseless.
"You dare speak of matters you cannot possibly comprehend!" Avery raged, his voice seeming to boom from every direction within the roiling sphere of darkness. "I am the last, true heir of the Dark Lord! Born to resurrect his noble purge of the unworthy from our hallowed wizarding realm!"
There was a nauseating lurch, and suddenly Avery's serpentine face loomed before them, twisted with insane ambition. Just as suddenly, he was replaced by a revolting vision of Voldemort himself, crumbling to ashes in the Forbidden Forest.
"He was cheated of his rightful supremacy!" Avery's booming voice accompanied the horrific visuals overwhelming their senses. "But from the anguish of his battle here, a shard of his very essence lived on..."
Abruptly, the images shifted once more to reveal a horrifying facsimile of Avery's mother, Griselda, heavily pregnant. Her gaunt features twisted with rapturous devotion as she sensually caressed her swollen belly.
"From that lingering spark, joined with the superior purity of my mother's womb...I was conceived! To one day finish what my ineffable father began!"
With a thunderous crescendo, the sphere of shadows burst apart in an explosion of light and sound. Avery stood before them, wand aloft, his face flushed with dark power and fanatic zeal. Off to the side, the grisly display of Nagini and the bone shards were now horrifyingly visible.
"And soon..." he snarled through gritted teeth, "...I shall wield a wand imbued with the full, indomitable essence of Lord Voldemort's magic itself! Forged from my very flesh and blood, its power will be beyond comprehension!"
Albus felt tendrils of ice crawl up his spine at the sheer depth of Avery's depravity. From the corner of his eye, he could see his own father's face etched with sober resolve.
"I'm sorry, Malcolm," Harry spoke, low and solemn. "For whatever existential anguish warped your soul down this path of delusion."
His wand arm raised, bathing the Chamber in a brilliant emerald light.
"But we cannot allow you to go any further down this road of darkness!"