The syllable had barely left Cassius's lips when the world detonated.
It almost didnt feel like magic, more like Cassius had simply called forth the ghost of a terrifying demon instead.
A sudden, crushing, primordial pressure slammed down over the classroom like a tidal wave.
Several students collapsed instantly, knees hitting stone with painful cracks.
Others screamed.
A few—mostly Slytherins—went very still, as if they instinctively understood that any movement might draw attention from whatever ancient thing was about to appear.
Shadows vanished.
Dust evaporated.
The torches along the wall guttered violently, struggling to exist in the presence of something far older, far holier.
As the spell finalized the purple shape finished materializing and phasing into view—titanic, coiling, wings unfurling with the slow majesty of ancient glaciers thawing.
A dragon formed in ghostly, incandescent starlight.
Not faint. Not translucent.
Corporeal.
Vast.
Divine.
The creature's head alone was the size of a carriage.
Its horns arched like obsidian crescents crowning its head.
Its wings stretched wall-to-wall, brushing stone and ceiling alike, forcing the classroom to expand with cracking pops as space bent around it.
Even half the size of Serepha—even that—made it a monster compared to anything Hogwarts had ever seen.
Students flattened themselves against walls or ducked beneath desks, trembling uncontrollably.
The dragon's eyes opened.
Eyes not focused on anything in particular as if they simple saw everything without needing to look for it.
And every student felt it.
The oppressive, holy might.
The authority so absolute it drowned thought.
The crushing aura of the first ever known dragon patronus.
Looking everybit like the murals he'd seen not to long ago within the caslte of Camelot.
The one considered a primordial force of creation and destruction, the patriarch of the true dragon race, from which spawned all other dragons.
Akon Kagura.
"Sweet… MERLIN—" Parvati choked, collapsing.
Neville fainted on Seamus, who fainted on top of Neville.
(A/N Head on lap, then head on back)
Draco Malfoy, to his future eternal shame, squealed like a stepped-on kneazle and dropped into a bow without meaning to.
Even Hermione and Daphne—strong-willed, brilliant, stubborn both—found themselves clutching to one another as their eyes locked onto Cassius seeking solace, barely upright by sheer force of will.
Comparing this creation to the Stag or even the girls own otter, and fox would be insulting.
Harry Potter himself fell onto one knee, eyes wide, breath shaking.
Not in awe.
In primal fear.
Lupin didn't fall.
But he went very, very still.
His eyes reflected the dragon like it was an eclipse.
His voice—when it finally came—was barely a whisper:
"…Impossible."
The dragon lowered its head toward Cassius.
Not simply acknowledging him.
Recognizing him.
Claiming him.
A deep, world-shaking rumble filled the air as its snout hovered inches from his chest.
Heat washed over him—pure, radiant heat, such that it felt like his very soul was being warmed.
Cassius swallowed.
Hard.
"…Uh. Hi?"
The dragon's eyes softened.
Just slightly.
A sound like a low, resonant purr thrummed through the classroom.
Every window rattled.
Nearby glass cracked.
Then—very gently for a creature the size of a small building—it nudged Cassius's shoulder.
A mark of affection.
Of protection.
Of oath.
But for Cassius what mattered most was the feeling.
Patronus's arent physical beings and yet his own patronus had just nudged him.
But rather than passing through him like a ghost, instead he actually got nudged.
Having a magical patronus was indeed rare, but having one that could actually interact with the physical world.
Now that was even rarer still, to his knowledge the only one that should have a patronus capable of doing the same right now would be Ronald Weasley, with his dog patronus capable of slightly interacting with the world as it passes through things.
So for Cassius to not only possess a Magical Creature as his patronus but then also to have that same patronus be capable of almost total formation such that it feels real was mind blowing.
Seeing the fact he suceeded and the state of the rest of the class he quickly halted his flow of magical power ending the spell.
Letting the dragons form to phase out of existance once more returning to whence it came.
But even after the dragon was gone the class remained still no one moving or even wanting to believe what they had just seen.
"So... did i pass?" Cassius asked impishly to Lupin, while at the back of the room Sirius was busy slowly pulling down his sunglasses staring at his godson in wonder.
Either at the epic class level prank he just pulled off, or at the sheer magnitude of the regular thing he had just performed instead.
As for the class only Hermione and Daphne were capable of moving, but they looked like newborn fawns walking on shaky legs as they made their way to Cassius before diving into his embrace.
At first he thought they were seeking comfort, but before long their hands started to roam as if trying to check and see if he had somehow sustained injury due to the summoning of his spirit guardian.
Still now having a bonk stick he simply settled for a simple karate chop to the heads of both girls, ceasing their wandering hands, while he also moved to separate them from his body, especially seeing as how the class had broken from their state was all eyes were now locked on the three of them.
Turning round to see the same the girls faces practically exploded rushing to get away, meanwhile the center of attention Cassius still just calmly stood there, looking once more at Professor Lupin.
"So Professor...? Did i pass? Or would you like me to cast the spell one more time?" Cassius's words were playful knowing full well he'd get top marks if not more if this was a gradeable endeavour.
"Er... yeah most excellent spellwork, Mr. Snape, just what we've come to expect from your genius." Lupin replied though his face itself appeared strained.
Meanwhile at the back of the room Sirius having pulled his own wand out was casting his own Patronus with a strained face, he suceeded in the casting but the look of constipation clearly exposed to Cassius that the man was petty seeing his great beast and was trying to will his Shaggy Dog into, perhaps a Cerberus or even a Dire Wolf.