The golden autumn at Hogwarts eventually gave way to the biting chill of a Scottish winter, and with the change in season, the sensationalism surrounding the Chamber of Secrets began to cool as well. Students, being the resilient and somewhat distractible creatures they are, soon found new things to obsess over. The Hufflepuff-Ravenclaw Quidditch match, the mystery of why the moving staircases were suddenly squeaking, and the looming threat of end-of-term exams replaced the whispers of basilisks and ancient heirs.
Life returned to its rhythmic, magical grind. Sebastian, however, remained at the center of a whirlwind he had created. His schedule was a logistical nightmare that would have made a Time-Turner weep. Between grading Muggle Studies essays on the "Strategic Importance of the Internal Combustion Engine" and leading the Auror Training Class through high-intensity tactical drills, he was also busy nurturing Luna Lovegood's unique grasp of Emotion Magic.
Yet, beneath the surface of his busy teaching life, Sebastian's mind was anchored in the depths of the third floor. Specifically, in the notes he had liberated from Salazar Slytherin's secret office.
While the rest of the castle slept, Sebastian sat in his study, surrounded by stacks of ancient parchment and modern analytical charts. He wasn't just reading Slytherin's journals; he was dissecting them. He was comparing the Founder's eleventh-century observations with the modern understanding of the Animagus transformation—a branch of Transfiguration that had remained largely stagnant for centuries.
In the wizarding world, an Animagus was a reflection of the soul. You didn't choose your animal; the animal chose you based on your deepest essence. If you were a stubborn, protective sort, you might become a bear. If you were shifty and observant, perhaps a rat. It was a passive process, an internal mirror.
Slytherin, however, had looked at that mirror and decided to smash it.
His research was a radical departure from tradition. He didn't want to find the animal within; he wanted to insert a monster from without. By using the blood of magical creatures as a catalyst, he sought to override the wizard's natural resonance and forcibly rewrite their biological code. It was the ultimate magical hack.
As Sebastian delved deeper into the journals, the reasons for Slytherin's failure became glaringly obvious through a modern lens.
"Salazar, you brilliant, stubborn idiot," Sebastian muttered, leaning back in his chair as he rubbed his eyes.
Slytherin's first mistake was his lack of experimental control. In his hunger for results, he had jumped from creature to creature. One month it was a dragon, the next a manticore, then a bigfoot. He was treating his own body like a mixing bowl. Each failed experiment left behind residual magical markers—"ghost" signatures in his bloodline. By the time he reached his third or fourth trial, his own biology was a battlefield of conflicting magical information. No wonder he started looking like an ape; his DNA was essentially screaming in ten different languages at once.
Sebastian realized that for this to work, there could be no "trial and error" on the same subject. You had to pick one creature, one bloodline, and get it right on the first try. The margin for error wasn't slim; it was non-existent.
The second mistake was more subtle: the "Will of the Blood."
Magical creatures aren't like mundane dogs or cats. Their blood carries their consciousness, their predatory instincts, and their ancient temperaments. When Slytherin tried to transform into a Dragon, he wasn't just changing his shape; he was inviting a thousand years of reptilian rage into his mind. Because he didn't know how to strip the "ego" from the blood, the Dragon's consciousness fought him for control of the steering wheel. He'd had to abort the transformation just to keep from becoming a mindless beast.
"This is where you needed Rowena," Sebastian whispered to the empty room.
Slytherin had been a master of Power and Ambition, but Rowena Ravenclaw had been the master of the Mind and Emotion. If the two had worked together, Rowena could have used her Emotion Magic to "sanitize" the blood—to scrub away the creature's personality while leaving the physical blueprint intact. But the Founders were a prideful bunch, and Slytherin's ego wouldn't let him ask for help with a project that smelled of dark arts.
Now, a thousand years later, Sebastian stood on the shoulders of these giants. He had Slytherin's blueprints and a mastery of Emotion Magic that even Ravenclaw might have found impressive. He could bridge the gap.
But the question remained: what should he become?
His first thought, naturally, was a Phoenix. Dumbledore's companion, Fawkes, was a constant reminder of the perks. Immortality via rebirth, the ability to bypass almost any magical ward via flame-travel, and tears that could heal a mortal wound. It was the "prestige" choice.
However, as Sebastian analyzed the Phoenix's blood-data, he shook his head. "Too fragile," he noted. A Phoenix was a support class, not a tank. If you got hit by a powerful enough curse, sure, you'd turn into a chick and come back later, but in the heat of a duel, that was just a very flashy way of losing. He needed something that didn't need to die to win.
Then he considered the Eastern Qilin. It was majestic, powerful, and lived in a state of high-vibrational magic. But the Qilin had a "purity" requirement. It could sense the soul. Sebastian looked at his own reflection—a man who had manipulated timelines, stolen secrets, and played the world like a chessboard.
"Yeah, me and a Qilin wouldn't get along," he chuckled. "I'd probably give myself a magical allergic reaction the moment I shifted."
He ran through a list of other candidates. A Thunderbird? Great for weather control, but a bit too chaotic. A Demiguise? Invisibility was useful, but he could already do that with a high-level Disillusionment Charm. A Dementor?
"Ugh, no. I like being able to taste my food," he muttered, crossing the soul-sucking option off the list.
The more "unique" the magical talent, the more complex the blood information was. Trying to transform into a Phoenix meant trying to process the concept of "Eternity" and "Rebirth" into your cells. The math was staggering. To ensure a 100% success rate, he needed a creature that was powerful, but simple.
He finally narrowed it down to two choices: The Dragon and the Troll.
A Dragon was the gold standard of magical apex predators. Their hides were naturally resistant to almost all standard spells. Their physical strength was off the charts. They were, in essence, flying tanks. Their "magic" was straightforward: they were big, they were tough, and they breathed fire. The information in their blood was largely physiological—muscle density, scale hardness, lung capacity. It was a "clean" file that a human mind could easily fill without being overwhelmed by alien instincts.
The drawback was the magic cost. Powering a body that weighed several tons required a massive internal battery. Fortunately, Sebastian's magical reserve was more like a power plant than a battery.
Then there was the Troll.
Trolls had incredible regenerative properties. You could chop off an arm, and they'd just grow a new one. They were remarkably magic-resistant, mostly because they were too stupid to realize they were being cursed.
Sebastian stared at the "Troll" option for exactly three seconds before bursting into a fit of quiet laughter.
"Imagine," he said to his cat, who was watching him from the bookshelf. "The Great Sebastian Swan, Master of Alchemy, Professor of the Year... turning into a ten-foot-tall stinking brute with a club. I'd lose the 'best dressed' award instantly."
He sighed and crumpled the paper. "Only a fool—or a very desperate wizard—would choose a giant monster that spends its life smelling like a wet basement. I have a reputation to uphold."