"So, Professor Rosier," Dumbledore said, settling back in his chair. "It's been some time since you last walked these halls."
"Not nearly…" Cassian muttered before catching himself. He cleared his throat, forcing a brittle smile. "Er… yes. A while."
Dumbledore chuckled. "You were quite the student. If I recall correctly, your attendance record was… creative."
Cassian tilted his head. "I prefer to think of it as prioritising."
"Of course." The twinkle in Dumbledore's eye brightened. "And now, you've chosen to return in an entirely new capacity. A fascinating turn of events."
"Chosen is a strong word," Cassian said, leaning back. "Let's say I was strongly encouraged."
"Ah," Dumbledore mused, fingers steepled. "Family expectations, I presume?"
Cassian scoffed. "You could say that. Apparently, I am not entirely useless if I can stand in front of a room and talk without drooling."
"I suspect there is more to it than that," Dumbledore said, his tone light but watchful. "Your Summer Festival lecture caused quite a stir, Professor Rosier. Many experienced wizards understand the importance of intent, visualisation, and mental imagery when casting spells. But your take on spell variation… relying on mindset rather than suffixes was new to me as well. I must admit, I've always used incantation modifiers for variations. But after your lecture, I tested your theory, and, as you pointed out, the extra words were unnecessary."
Cassian arched a brow. "So, what you are saying is, I taught Albus Dumbledore a new trick? And they say you can't teach new tricks to… ah… learned, distinguished gentlemen."
Dumbledore chuckled softly, that infuriating glint in his eyes as though he already knew the punchline to a joke Cassian hadn't heard yet. "A rather humbling experience, I assure you."
Cassian leaned back slightly, arms folding across his chest. He hadn't expected that. Not because he thought Dumbledore was above learning… clearly, the old man had spent a lifetime doing just that, but because most wizards wouldn't bother re-examining something as basic as Lumos. They just did what worked and never questioned why.
"Well, glad to be of service," Cassian said. "But I have to say, if you were testing out spell mechanics based on my half-baked ramblings, you must've been terribly bored."
Dumbledore's smile was faint. "On the contrary, I found your perspective refreshing. It is rare to hear magic discussed in such terms, particularly from a young wizard."
Cassian lounged back, arms draped across the chair. Fake it till you make it, right? "Hopefully, the students enjoy my lessons. Last I checked, History of Magic was just a convenient excuse for a nap."
Dumbledore chuckled, his eyes twinkling. "Yes, Professor Binns' lectures do have that effect. Many students find themselves resting their eyes, though I suspect few actually intend to sleep through the entire lesson." He tilted his head slightly. "I am curious… how do you plan to make it more engaging?"
Cassian shrugged, a half-smirk tugging at his lips. "Well, considering I spent most of my school years perfecting the art of looking awake while being anything but, I think I have an advantage. If nothing else, I know exactly what not to do."
Dumbledore's amusement didn't fade. "A promising start, I must say."
"History is not the problem," Cassian continued, drumming his fingers against the armrest. "It is how it is taught. Just dates and names thrown at students until it all blends together. No wonder half of them would rather drool on their desks." He leaned forward slightly. "History isn't dates and dusty names… it is about why. Who pulled the strings? Who bled for it? Who got rich while everyone else rotted? That is what matters. That is what makes it interesting."
Dumbledore nodded, considering him. "A perspective that few educators take. Most prefer the safety of neutral storytelling."
"Neutral is just the polite word for boring," Cassian drawled, flicking his fingers dismissively. "Besides, history is never neutral. Every story depends on who is telling it. Even in y- our world."
Dumbledore's expression sharpened ever so slightly. "Indeed."
Cassian didn't miss the shift but didn't comment on it. Instead, he stretched his legs out a little. "I am not planning to turn this into a political debate every lesson, don't worry. But if they leave my class actually remembering something other than the year of the Goblin Rebellions, I will call it a win."
"A noble goal," Dumbledore mused. "And one I believe you may achieve, given the right approach." He gestured toward the desk, where a folder sat neatly atop a stack of books. "Your schedule, class lists, and curriculum guidelines. I suspect you may find them… flexible."
Cassian arched a brow, reaching for the folder. "Flexible as in 'we trust you to handle it,' or flexible as in 'figure it out yourself'?"
"A bit of both, I imagine."
Cassian flipped open the folder and skimmed the student list. Plenty of familiar names… Weasleys, Rosiers, a few other pure-blood families that had been clinging to relevance for generations. But no Harry Potter. His brow twitched slightly.
That was the only name he actually knew from the books. Well, knew was a strong word. It was plastered all over the world once, enough to gather that the kid was important, but beyond that? Nothing. No idea if he was supposed to be here yet, if he'd already come and gone, or if this was some completely different timeline where Potter had never existed in the first place. 'No wait, old Cassian remembers the boy who had killed their lord.'
Not that it really mattered. He had enough to deal with without worrying about some boy who may or may not have been famous in a story he never read.
He flipped another page, skimming schedules, lesson plans… well, loose guidelines, at best. Dumbledore hadn't been lying about the flexibility. Half of it was just, "Cover major events and figures. Don't bore them to death."
Solid advice.
Cassian leaned back in his chair. "So, just to be clear, I can teach however I want, as long as no one sets fire to the classroom?"
Dumbledore smiled. "An accurate, if simplified, understanding."
"Brilliant." He shut the folder. "Anything else I need to know, or can I start traumatising students immediately?"
Dumbledore chuckled. "I imagine you will find Hogwarts much the same as you left it."
Cassian doubted that. He... Old Cassian had spent most of his school years avoiding anything that required effort, and now he was expected to stand at the front of a classroom and act like an authority on something.
Well. He was an authority. Just not in the way they thought.
He stood, shaking Dumbledore's hand. "Guess I will see you at the next staff meeting… or in detention. I am nothing if not versatile."
"Let's hope for the former." Dumbledore's eyes twinkled as always, like he knew more than he let on. Cassian didn't know if it was magic or some sort of brilliance of an old master seeping through. Cassian ignored it, nodding before heading out.
The corridors were just as he remembered… stone, portraits, the occasional ghost floating about like they had nowhere better to be. It was surreal, walking through the place again, this time as a professor. He wondered how many of the old staff were still around. Probably McGonagall. She seemed too stubborn to die.
Reaching his quarters, he found his luggage already inside. House-elves, probably. He shut the door behind him and exhaled.
Alright. Time to figure out how the hell he was going to pull this off.
***
As he sat, Cassian closed his eyes and let his mind drift back to the list.
And then, he nearly choked.
Lumos - First Year Spell - [Maximum Mastery]
What.
The last time he checked, it had been sitting at [Insufficient Mastery], creeping up slowly as the lecture went on. But now? Maximum Mastery.
That wasn't normal. Hell, he wasn't normal, but this? Something wasn't adding up.
He rubbed his temple, going over it again. He hadn't suddenly become some prodigy at spellcasting overnight… he knew that much. His Lumos had barely been holding together a few weeks back. No sudden spark of genius, no months of secret training. So why the hell was it maxed out now?
Unless…
His mind jumped back to the lecture. The crowd. The way they'd been hanging on to every word, actually trying the spells.
Could it be that?
Cassian frowned. He never heard of magic working like that. Normally, if someone taught a spell, the student got better, not the teacher. That was just common sense. But here he was, staring at undeniable proof that something weird was going on.
Maybe it was some kind of shared effect? Magic responding to the fact that over thousand people had learned Lumos through him? It didn't make much sense, but neither did half the things he'd seen in this world so far.
He tapped his fingers against the armrest, thinking. If that was the case, then… what? Every time he taught a spell and someone learned it, he mastered it completely? That was ridiculous. But so was waking up in a body that wasn't his, so was pulling lost spells out of thin air, so was everything.
He exhaled. If it was connected to teaching, then he had a way forward. An advantage. He just had to figure out how far it went. Would it work on any spell? Did the number of people learning matter? If one person learned a spell from him, would that be enough?
No way to know without testing it.
And lucky him, he had an entire school full of students about to be forced to listen to him.
Cassian snorted, shaking his head. Well, guess I am about to be the best History of Magic professor this place has ever seen.
(Check Here)
--
You stand before the mirror.
It shows you…
Cassian, holding a glowing Power Stone.
Behind him, Bathsheda Babbling smiles approvingly.
You reach for the reflection.
It laughs.
"You don't even have one," Cassian says.