Harry Potter and the Surprisingly Competent History of Magic Professor

If you like to see Images of Cassian and Bathsheda, I added an auxiliary chapter. You can find at the top of the chapter list.

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Cassian pulled a rough chunk of stone from his desk, placing it in front of him. Then, from his robes, he pulled a small knife. Without warning, he stabbed the blade into the rock. A sharp crack echoed through the room as dust scattered from the impact.

"Stone is rigid. Push hard enough, and it shatters. That is true of rocks, bones… even kingdoms," he said, dusting off the handle and set it down, instead pulling his wand. "Now, watch."

He muttered, Spongify. A faint shimmer passed over the stone's surface. Cassian grabbed the knife again and stabbed down hard. Instead of cracking, the stone compressed slightly, absorbing the impact like thick rubber. The blade bounced off harmlessly.

A few students leaned forward, intrigued. Others glanced at each other, eyebrows raised.

"Professor, could you really use it to jump off a tower without splattering?" a Slytherin asked, half-joking.

Cassian raised an eyebrow. "If your goal is to bounce like a deranged Quaffle, sure. But you would better hope your aim is flawless. Miss the spell by a hair and all they will find is a very squishy crater that needs cleaning."

A few students laughed nervously.

"Anyone else want to suggest launching yourselves off towers? Or shall we try for a question that won't make me lose faith in magicks-kind?"

A Ravenclaw raised her hand timidly. "Could it be used on armour to soften incoming blows?"

"Now that is a proper question," Cassian said, nodding. "It was used as such… especially before Shield Charms became widespread. Though if you are softening armour, make sure you undo it before someone stabs you. You won't like how it feels when a blade sinks through like butter."

"In medieval times, Softening Charms were common in duelling. Instead of dodging spells, some wizards softened even their own skin to absorb impacts without injury. Healers used them for setting bones… less risk of fractures snapping completely. And, of course, thieves loved them. Made locks easier to break, floors quieter to walk on, and walls less of a barrier if you knew where to cast."

"Though, keep in mind, it is effective against blunt objects, but not so much against sharp ones." After making sure there weren't more ludicrous questions, he continued.

"Softening Charms aren't just for making the floor more comfortable when you fall on your arse off your broom," Cassian said. "They were used in ancient construction to shape stone before wizards had precise Transfiguration. They made carving easier, moving materials simpler, and even dampened vibrations to prevent buildings from collapsing during earthquakes."

He gestured to the board, where the words shifted… Applications Through History.

A student tilted her head. "And in modern use?"

Cassian thought of explaining how the same spell could be used in many ways in the modern age as well, but felt it would cause more confusion. Instead, he said, "Magic shifts with time. What started as a battlefield spell ends up a convenience charm. Give it a century, and someone will use it to make sofa cushions fluffier. What was practical a thousand years ago might seem pointless now… until you need it." 

He flicked his wand, and the illusions vanished, along with the floating words. "Optional homework… non-mandetory, you can write a two-foot essay on practical uses of the Softening Charm outside of duels. Think beyond the obvious. What does softening actually mean? What happens when a rigid structure loses its hardness? Apply it to anything… materials, magic, even history. Stretch your brains, if you remember how. And no! Don't cast Spongify to your brains to stretch it… As always, these are optional. I am not your Charms professor."

A few students scribbled notes. Others exchanged glances, weighing whether the effort was worth it. Cassian had already figured out who would bother with the assignment and who would pretend it didn't exist.

"That is all for today. Unless you want to spend the rest of class staring at me, you are free to go."

Chairs scraped against the floor as students packed up. Some left immediately, others lingered, discussing the lesson. 

Selena Rosier tapped her quill against the desk, watching him like he was some particularly strange puzzle she was trying to figure out. After a moment, she smiled softly, "Glad you found your passion, Cousin."

Cassian chuckled, tucking his wand back into his sleeve. "Took a while, but I suppose it is in the blood." He gestured toward her notes. "How is spell creation treating you?"

Selena leaned back, crossing her arms loosely. "Better than expected. Master Goshawk actually acknowledged my last submission. Said it had potential."

Cassian raised an eyebrow. That was no small feat. Miranda Goshawk wasn't just any spell theorist… she was the spell theorist. If she thought something had potential, it meant something.

"Impressive. What does it do?"

Selena looked away, probably considering if it was safe to say. She must have decided it was, as she said, "It is a stabilisation charm. Works on unstable enchantments… wards, runes, experimental spells that are on the verge of collapse."

Cassian frowned slightly. "Wouldn't that make it ridiculously easy to reverse-engineer other people's work?"

Her lips curved. "Exactly."

He huffed a laugh. "Dangerous."

She shrugged. "So is half the magic we use daily."

He couldn't argue with that. Magic had never been safe… it just depended on who was wielding it. "When do you start the apprenticeship?"

"This summer. It is not official yet, but Master Goshawk hinted she would take me on if I keep up my work."

Cassian nodded. That was very official in Miranda Goshawk terms. "Guess we will have to toast to your inevitable world domination then."

Selena smirked. "Naturally."

She glanced around, checking the empty classroom before leaning in slightly. "Was it all an act? Before. When you were…"

Cassian smirked. "Almost a Squib?"

Selena sighed, unimpressed. "That. And the rest… kicking elves, torturing servants, acting like you owned the world."

Cassian sighed through his nose, running a hand over the worn cover of the book on his desk. How was he supposed to explain that the old Cassian was gone? That a different soul had taken his place? It wasn't something he could say… not that he would even if he would. The Rosiers weren't known for being forgiving, and obliterating someone's soul out of sheer offence felt entirely within their capabilities.

Instead, Cassian watched Selena with something between amusement and curiosity. "You tell me, Selena. You were always smarter than the rest of them. Are you not supporting our dear family's cause? Blood purity, Dark Lord, hating Muggles and halves?"

Selena's quill tapped lightly against the desk, as she gazed out the window. "You sound like Aunt Viola."

"Tragic," Cassian muttered, feigning a shudder. "I would hate to be mistaken for her."

Selena smiled but didn't rise to the bait. "I've never been one for blind tradition. Just because our ancestors worshipped idiocy doesn't mean we have to light the same candles."

"That is practically heresy," Cassian said, deadpan. "Great-great-great-great Grandmother Serphia is going to crawl out of her grave and hex you for that one."

Selena rolled her eyes. "Oh, please. Grandma Serphia would've burned half the family for being incompetent bootlickers." She rested her chin on her hand, gaze lcoked on him. "You didn't answer my question, though. Was it all an act? Before."

Cassian shrugged. "Would it make a difference?"

She studied him for a long moment, as if weighing his words against what she remembered. "Not really," she admitted. "But it is strange. You used to be…"

"An arse?"

"I was going to say a spoiled, arrogant waste of potential," Selena said, smiling mischievously "But yes, that too."

"Flattering," Cassian said. "And now?"

Selena considered. "Still an arse, but significantly less of a git. Though I suppose teaching history isn't the worst thing you could be doing."

Cassian scoffed. "High praise from a Rosier."

"I like to think I have some taste," she said, then adding softer. "You are actually good at this. Teaching, I mean."

Cassian exhaled, glancing at the now-empty classroom. "Turns out I enjoy it."

Selena gave him a look, half-incredulous. "That might be the most shocking thing I heard all year."

"Glad to keep you entertained." Cassian glanced at her notes. "To answer your question, it wasn't an act but self-preservation. You are smart enough to figure out the rest."

Selena didn't react right away. Her gaze flicking from Cassian to the board, then back to him.

"Hm." It wasn't agreement, but it wasn't disbelief either.

"Disappointed?"

She chuckled. "No, just… intrigued."

"By what?"

Selena tapped the end of her quill against her chin. "You. You've changed, Cousin. It is not just the teaching. It is like you woke up one day and decided to be… someone else."

Cassian smirked. "Must've hit my head."

"Hard enough to knock sense into you? Miraculous."

He chuckled, but the curiosity in her eyes didn't fade.

After a moment, she glanced at the clock and sighed. "I have Runes next. Try not to make too many enemies before lunch."

"No promises. And say hi to Professor Babbling."

Selena shook her head and packed up her things. As she left, Cassian turned back to his desk, gathering his own notes. 

(Check Here)

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Inscribed on the stone...

To the one who consumes but never gives

Their tea go cold.