HP: Too Late, System! I’m Already the DADA Professor

The Slytherin Defence Against the Dark Arts class representative, Cassius Warrington, and the Gryffindor class reps, the Weasley twins, weren't entirely sure what Douglas had in mind. But the way he drew his wand made one thing perfectly clear—whatever was coming next, it wouldn't be pleasant.

So, with forced grins stretched across their faces, both sides' leaders exchanged greetings that were anything but friendly.

Fred adopted the most cheerful tone he'd ever managed.

"Hi there, Mr. Warrington! Off to class, are you?

What a coincidence—we just finished!"

Cassius Warrington squeezed out a smile of his own.

"Yes, what a coincidence.

I hear your next lesson is with Professor Flitwick. You'd better hurry—he was just singing the Weasley brothers' praises in class!"

George feigned surprise.

"Oh, really? What exactly did Professor Flitwick say about us?"

Before he'd even finished, a few Slytherins snickered.

The twins' faces darkened. They were certain that kind, fair Professor Flitwick hadn't said anything flattering about them this time.

Across the way, Warrington arched his brows in open challenge. But in the end, out of respect for Professor Holmes—or, perhaps more accurately, out of respect for the wand in Professor Holmes's hand—neither side let things escalate.

With a chorus of cold snorts, the two groups stepped aside and passed each other without incident.

Slytherin's practical exam also began with their class rep. Perhaps it was because their common room overlooked the depths of the Black Lake, but as soon as Warrington entered the classroom and approached the pond, he immediately spotted the Grindylow lurking below.

What truly surprised Douglas was that Warrington cast a Bubble-Head Charm on himself before slipping into the water. The Bubble-Head Charm was usually taught in sixth-year Charms, and while Warrington's version looked fragile—liable to burst at any moment—it was still impressive for a fourth-year.

Maybe it was the confidence from the charm, or the fact that he'd noticed the Grindylow ahead of time, but Warrington breezed through the first challenge.

His trouble came at the second. Facing the troll, perhaps emboldened by his self-taught advanced spells, he unleashed a barrage of Petrification Curses, Stunning Spells, and Blasting Curses at the troll's thick skull—firing them off as if Galleons grew on trees.

But his aim was atrocious. Most of his spells missed or thudded harmlessly against the troll's hide.

Just as the troll dropped its guard, Warrington seemed to be charging up for a final, decisive spell. But at that very moment, his Bubble-Head Charm popped with a wet snap.

A wave of stench hit him full in the face. For a split second, Warrington looked like his skull might crack open from the smell. Then, clutching his stomach, he doubled over and vomited on the spot.

Even Douglas hadn't seen that coming. Who could've guessed such an ignoble defeat?

The magical creatures in the fourth-year practical classroom had a busy day. The Grindylow in particular bore the brunt—by the time Hufflepuff's fourth-years arrived for their afternoon lesson, the seventh-year student overseeing the classroom had to swap in a backup Grindylow so the original could get some rest.

By lunchtime, word of the fourth-year practical exam had spread across the entire school.

Younger students buzzed with envy—especially when they realized many of the dark creatures featured in the class were straight out of their own textbooks. Excitement ran high as they debated whether memorizing their books would let them challenge those magical beasts too.

The upper years were even more abuzz. If fourth-year practicals were this thrilling, what would fifth-year be like? The sixth-years who'd chosen Defence Against the Dark Arts were quietly dreading their turn. If Professor Holmes could bring all those textbook monsters into the classroom, surely their own lessons—like Inferi—would soon come to life as well.

Even though most had already finished their previous homework, a sudden sense of inadequacy sent them flocking to the library in search of every book on Inferi they could find.

Those who hadn't been selected for Defence Against the Dark Arts could only watch with envy, wishing Professor Holmes had taught them all along—surely their grades would have been so much better.

No matter how much chaos Douglas stirred up at Hogwarts, his classes continued with methodical precision.

After wrapping up the fourth-year lessons, he still had a Gryffindor second-year class and a sixth-year session to teach that afternoon.

Looking at the two towering stacks of homework he'd collected, Douglas couldn't help rubbing his temples. Was he assigning homework to them, or just to himself?

When Hermione reported that everyone had finished memorizing the previous lesson's content, Douglas glanced at Neville, who was practically glowing with excitement. According to Hermione, Neville had been getting up at six every morning to study in the common room, determined not to hold anyone back.

Douglas gave Neville an encouraging look, then generously awarded Gryffindor twenty points.

But as the rest of the students looked at him with hope, clearly expecting a hands-on session with magical creatures, Douglas instead had Hermione lead them in reading the next chapter twice, then required everyone to memorize it in full.

There was a brief chorus of groans, but under the relentless supervision of class rep Miss Granger, their spirits quickly bounced back.

"Don't forget," she reminded them, "the professor promised—once we've all memorized the text, he'll take us for a practical lesson!"

Douglas was thoroughly pleased with Hermione's performance. The girl wasn't just a scholar—she had the makings of a politician. If memory served, he'd heard somewhere that Hermione ended up at the Ministry of Magic after graduation. As the saying goes, the child is father to the man.

While the students recited below, Douglas quietly cast a Muffling Charm of his own invention—a spell that plunged the caster into total silence, like having magical earplugs. He'd always remembered a spell called Muffliato, but after scouring countless spellbooks, he'd never found it. Maybe it was one of those original inventions by the Half-Blood Prince, Severus Snape.

He'd even rifled through the old classroom cupboards, hoping to find a copy of Advanced Potion-Making—but no luck. Later, after asking a Hufflepuff sixth-year who took Snape's class, he learned that the sixth- and seventh-year Potions classrooms were separate from the lower years, since advanced brews needed more time and space.

Douglas had planned to quietly borrow that textbook once he reached sixth year. After all, besides Snape's original spells, it was said to contain invaluable notes on potion-making.

But who could have guessed that Snape wouldn't even give him the chance to enroll in Advanced Potions?

Hmph! Pride and prejudice!

Douglas silently scorned Snape.

~~~❃❃~~~~~~~~❃❃~~~

Explore More Amazing Fanfiction on My Patreon!

Unlock 30+ Advance Chapters and Enjoy Exclusive Stories Early!

👉 patreon.com/GoldenLong