There was no such mechanic

Late at night on my last day before discharge, the wall lamp in the ward was very dim.

Cordelia was already fast asleep on the small bed next to her, her hands still tightly gripping Gavin's sheets, occasionally muttering a few words in her sleep.

"Two days have passed. Have you decided how you want to die?"

Gavin leaned against the headboard, staring indifferently at the "Book of Ten Thousand Spirits Calculation" spread out on his lap.

The black Diary shuddered, its previously droopy pages laboriously turning to reveal a few lines of weak, yet still stubbornly persistent, cursive handwriting:

[Death? How could that be! How could the great Book of Ten Thousand Spirits Calculation be stumped by a mere 15% gap in the origin?!]

[Master, you greatly underestimate the wisdom of this Calculation Book!]

[To help the beautiful and kind mistress resolve her troubles, this Calculation Book has been working tirelessly these past two days, burning the midnight oil, and has already derived a flawless solution for you. But before that—]

[Master, could you praise me first, and maybe even give me a meal?]

A wisp of Black Flame appeared on Gavin's hand:

"It seems you've decided you absolutely must die."

[No, no! Master, let's talk this out! I'll write it right now! I'll write it right away!!]

The fancy handwriting on the paper instantly faltered, then flipped to a blank page and presented the deduction result:

[Optimal Solution 1: The unknown pale blue potion ("God's Potion") intercepted by the master in Romania.]

[The empirical evidence presented by the dragon-form wizard Dachian shows that he can directly regenerate severed limbs and allow damaged flesh to grow a second time, making it the most likely solution to break through the limits of life!]

"The God's Potion?"

Gavin raised an eyebrow, looked at the paper, and asked:

"Are you sure that stuff works? I vaguely remember back in Romania, Dachian went into a frenzy after drinking it, and it seemed more like he was draining his Life Force."

[Master, you are wise! Judging from Dachian's reaction, this is indeed the case. However, the effects of that potion are truly unique. This Calculation Book has determined that there is a 68.3% probability that, after certain modifications and dilutions, it can affect the composition of the life vessel!]

"Real?"

[Absolutely true.]

"That blue potion?"

Gavin muttered to himself.

He had almost forgotten about it if the Calculation Book hadn't been mentioned.

Previously, he had given the Half-Blood Prince along with the Basilisk's corpse.

Speaking of which, Snape has been around for so long, he should have some clues by now, right? I might as well ask him.

He put those thoughts aside and continued reading.

[Option Two (Possible Alternative): Nicolas Flamel's "Elixir of Life"]

[Conventional supplements cannot exceed the limits of their capacity, but Nicolas Flamel survived for over six hundred years thanks to the Elixir of Life, proving its fundamental power to maintain and extend the origins of life!]

After reading the last line, Gavin noticed a pitiful little beggar's bowl drawn at the bottom of the page:

[Report complete! The great Calculation Book is starving! Please, Master, grant us food!--]

[Just give me a book, I can do anything!]

Gavin glanced at the paper, and his expression softened slightly.

This damned book did something decent before it died.

He raised his left hand and placed it on the spine of the book, transferring a small amount of Life Force to it, then casually closed the Black Book was happily rubbing against his palm.

The two directions derived from the Calculation Book were actually quite similar to what he had in mind, serving as a kind of mutual verification of those directions.

Nicolas Flamel could obviously live forever with the help of Elixir of Life; he just wouldn't look so young anymore.

But Cordelia certainly wouldn't like that.

So let's list it as an alternative for now.

Meanwhile, Dumbledore previously mentioned that the formula for the Elixir of Life had been destroyed along with Nicolas's death, and the pale blue potion in Snape's hand was now more readily available.

In addition, Gavin considered another possibility.

He had previously speculated, while researching the consumption of Obscurus, that Magic might also have the function of prolonging life.

The wizards' exceptionally long lifespans, and Jacob's ability to carry heavy loads on foot at the age of 93, despite living in a magical environment for so long, all illustrate this point well.

Previously, his own Magic was too loose to be effective.

However, the performance of Gavin's white vortex and the Obscurus when they were activated together in this parallel world perfectly confirms this point.

The Calculation Book had not yet synchronized its memories from the other world, so it was unaware of this.

If only Cordelia's Magic could be made to look like that...

Externally, it relies on God's Potions and the essence of the Philosopher's Stone to replenish its limits; internally, it relies on high-density pure white Magic to compensate for its depletion.

With a two-pronged approach, Cordelia's 15% shortfall will eventually be completely filled.

Thinking about this, Gavin suddenly had a question:

"How do you cultivate Primordial Qi?"

Early the next morning, in the underground Potions Classroom.

As soon as Gavin sat down in the center of the first row, a low murmur arose in the classroom.

The badger cubs in the back row were beaming with delight, while the Ravenclaws on the other side froze, their hands still turning the pages, their eyes filled with awe.

This academic genius, who single-handedly shattered all their stereotypes about Hufflepuff, usually forced them to be on their toes in every class.

The eaglets finally got a three-week break while he was hospitalized.

When I looked up today, the tallest mountain was back.

Under the complex gazes of the entire class, Rolf, sitting next to Rolf, shrank back and trembled as he gripped the Copper Balance, looking like a Flobberworm about to be dissected.

The school bell hadn't rung yet, but Rolf hoped it would never ring.

But Gavin, sitting next to him, was acting out of character today. He had his hands in his sleeves and was smiling as he looked at the closed office door behind the podium.

Seeing him like this, Rolf felt increasingly uneasy and couldn't help but lean closer, lowering his voice and asking in a trembling tone:

"Gai, Gavin... you just got out of the hospital, why are you smiling so happily? It scares me..."

"Is there?"

Gavin slightly suppressed the corners of his mouth, thought for a moment, and then said with deep emotion:

"It must have been a full three weeks since I last saw Professor Snape. I miss him terribly."

"Ha?"

Rolf dropped the bronze weight in his hand onto the table with a clatter, and his gaze toward Gavin changed.

Oh no, Madam Pomfrey definitely didn't cure Gavin.

Has he gone mad from lying in his hospital bed?

Just as Rolf was figuring out if it was too late to use the excuse of carrying Gavin back to the Hospital Wing to ask for leave—

Bang!!

The small door behind the podium was kicked open from the inside and slammed heavily against the stone wall.

Snape strode up to the podium, his wide Black Robes billowing behind him like a dark cloud. He skipped the roll call, drew his Wand, and swung it heavily across the blackboard, instantly producing lines of chalk writing:

"Today we're making Confusing Concoction. The steps for preparing the ingredients are on the blackboard."

After saying this, Snape coldly glanced at the students below the stage, only to find that the entire class was looking at Gavin in the first row, and not a single person made a move.

Snape's narrow eyes narrowed dangerously, his voice as cold as ice squeezed from between his teeth:

"What, do you want me to write the invitations myself and then ask you to begin?!"

Whoosh--!

The entire class of young wizards was terrified, and in an instant, the sounds of chopping angelica and scrubbing cauldrons filled the air.

Only the first row, right in the center.

Gavin didn't even touch the silver knife in front of him; he remained standing there, smiling as he looked up at Snape on the podium.

Snape's temple throbbed; he felt challenged.

So he strode to the front row of tables, looked down at Gavin, and frowned.

"Mr. Gu, have you been lying in bed for three weeks and made yourself stupid? Can't you even recognize the words on the blackboard anymore?"

"No, Professor."

Gavin met his gloomy gaze, his smile growing even brighter and more sincere.

"I just missed you so much, Professor Snape."

Click.

At the next table, Rolf almost chopped the Angelica pubescens at an angle, while Justin and Ernie in the back row nearly smashed their mortars on their feet. Several Ravenclaws looked up in disbelief, staring at Gavin in horror.

The entire Dungeon Classroom instantly fell into an eerie, deathly silence.

Gavin, however, seemed completely oblivious to the horrified expressions on the faces of those around him, and continued to press on with a smile:

"We haven't seen each other for so long, don't you have anything you want to say to me?"

Snape gave a cold laugh and squeezed out a sentence through gritted teeth:

"Hufflepuff, deduct 20 points, reason--"

"Trying to please the professor."

Upon hearing this long-awaited verdict, Gavin showed no sign of frustration. Instead, as if he had completed some kind of sacred ritual, he closed his eyes and let out a long, comfortable sigh.

This is the taste! Now I finally feel completely comfortable.

Looking at his strange, smug, content expression, Snape, standing by the podium, felt even more uncomfortable. His chest tightened, and he felt as if he had swallowed a whole live Slug.

Is this a new way to play pranks?

And this is just the beginning.

For the next half of the class, the entire class witnessed a spectacle unprecedented in the history of Potions Class—

Gavin Gu, who usually operates with the precision of Alchemy instrument, seemed possessed by Troll today:

They would either smash the slippery frog brains flat with a horizontal slice, splashing juice onto Snape's robes, or grab the entire Sneezewort, roots and all, and stuff it directly into the pot, sometimes even stirring it haphazardly clockwise and counterclockwise with a stirring stick.

He seems to be constantly provoking Snape.

"Who taught you to use the back of a knife to slap a frog's brain?! Hufflepuff, deduct ten points!"

"Sneezewort the pot without removing it by the roots? Are you trying to brew a pot of Poisonous Potion and send yourself back to the Hospital Wing?! Deduct another twenty points!"

"Stirring in the wrong direction! Is your brain full of Dungbomb? Hufflepuff, another 30 points deducted!!"

Snape was so enraged that his Black Robes billowed as he roared at the front desk, his shouts of deducting points nearly shaking the vaulted ceiling of the basement.

Strangely, the harder Snape slammed the ball in, the more genuine and radiant Snape 'Gavin smile became, eventually even smiling and nodding in agreement.

At the back console, Justin was completely dumbfounded. The pestle in his hand spun three times outside the mortar, and he nudged Ernie beside him in a daze.

"Ernie... is Gavin really insane?!"

Ernie swallowed hard, his face turning deathly pale.

"Madam Pomfrey may have missed one check," Ernie began with difficulty, "We should first confirm whether he remembers that he is Hufflepuff after waking up."

Gavin now looks exactly like a Pure-blood Gryffindor.

It wouldn't be an exaggeration to say that he is Godric Gryffindor himself.

To Gavin's left, Rolf's eyes had unknowingly reddened.

As he listened to the deafening roar in his ears and looked at his good brother's tall back, who was clearly skilled but deliberately used this clumsy mistake to draw all of Snape's anger onto him, a surge of hot heat welled up in his chest.

He finally understood!

Gavin isn't crazy at all.

Gavin knew he'd been getting yelled at every day in Potions Class for the past three weeks, and he was afraid that if Gavin made a mistake today, he'd be mercilessly berated by Snape again. So, as soon as he was discharged from the hospital, he risked ruining his image and took the brunt of Snape's pent-up rage for him for the entire three weeks!

"Good brother..."

Rolf's nose tingled, and he was so moved he almost cried on the spot. A deeply sincere thought popped into his mind—

No wonder Cordelia likes Gavin so much!

With such a gentle, reliable, and loyal friend... if Gavin weren't a man, I'd probably fall for him too, right?

We must not let Gavin's good intentions go to waste!

Rolf sniffed hard, his overwhelming emotion instantly transforming into boundless motivation. His hands flew across the control panel like butterflies flitting among flowers.

Weighing, grinding, controlling the heat, and stirring—all done in one smooth motion, without a single distracting thought.

So, when Snape finally finished berating Gavin, found an opening, and had amassed a torrent of even more vicious words, he turned to continue his tirade against Rolf standing nearby—

His words got stuck in his throat.

In the brass crucible in front of Rolf, a pot of perfectly potent, dark green Confusing Concoction, with its vapors rising in a standard spiral, had been successfully extinguished and set.

Snape stared intently at the Potions, which was flawless, for a full five seconds, before finally letting out a frustrated snort and dryly uttering:

"... It seems Mr. Scamander finally remembered to bring his brain with him before leaving home today."

Ring ring--

The bell finally rang, signaling the end of get out of class.

Gavin packed his bag and had just stepped out of the Dungeon Classroom when Rolf grabbed Gavin sleeve, his eyes brimming with tears and his voice trembling with emotion:

"Gavin! My good brother! I, Rolf, will remember your life-saving grace for the rest of my life!"

"Ah?"

Gavin blinked, looking completely bewildered.

When did I save your life?

"Don't try to hide it from me!"

Rolf was so moved that he kept wiping his eyes.

"Didn't you deliberately ruin the potion just to help me reduce the workload?"

"Is that so?" Gavin, somewhat doubtful.

He remembered that he had just been having Potions and wanted to get yelled at.

So that's how it is!

Ernie and Justin, who were standing nearby, suddenly realized what was happening and breathed a sigh of relief, exchanging a glance.

So Gavin wasn't crazy after all; it was all for Rolf.

He really--

Too kind.

Then, Rolf lowered his voice, his face full of worry:

"But Gavin, you drew all the attention for me and got at least a hundred points deducted by Snape for the whole class... Is that really okay? I heard that in his first year, Harry lost fifty points for staying out all night, and the whole of Gryffindor ostracized him for months!"

Justin and Ernie, who were standing nearby, also came over looking worried.

Gavin looked at his three roommates and shook his head with a smile:

"First of all, we are Hufflepuff, nobody cares about those few House Cup points."

"Really?" Rolf, somewhat skeptical.

"That's right." Gavin. "Look, you've already lost over 160 points to Snape in these three weeks, and you haven't even noticed."

"Huh?" Rolf's eyes widened. "So many?"

He turned to look at Ernie, Ernie did some mental calculations before raising his head and giving him a heavy nod.

Rolf slowly turned his head. "So, I should actually be worried about myself?"

"That's right."

Gavin paused, then held up his second finger, adding casually:

"Secondly, Hogwarts' hourglass does not have a penalty system."

Rolf, Justin, and Ernie were all stunned, their faces etched with utter naiveté.

"... What's the meaning?"

Just then, the heavy wooden door to the Dungeon Classroom was pulled open from the inside, Snape strode out with a dark expression.

Gavin, seemingly oblivious to the commotion behind him, smiled and solved the elementary school math problem for his three roommates:

"That means that during the three weeks I was hospitalized, Rolf had already deducted all of our house's points. This morning when I passed by the Entrance Hall, I took a look, and there were only ten points left in Hufflepuff's hourglass."

"So, Professor Snape's entire lecture just now, aside from that first point when he lost all ten points—"

Gavin glanced at Snape beside him.

"The 80 or 90 points deducted at the end were all ineffective."

The corridor fell into a deathly silence.

Rolf, Justin, and Ernie's mouths gradually formed circles as they stared at him in disbelief.

It can only be said that the little badgers really don't care about scores; they haven't even known for so long that the House Points is only 10 points.

And two steps behind them.

Snape, who had just stepped out of the classroom, suddenly stopped and froze on the spot for a full two seconds.

Then, without saying a word, he abruptly flung his Black Robes back into the classroom, grabbing the heavy Oak door behind him.

Bang--!

A deafening roar echoed through the underground corridor, causing Dust to fall from the cracks in the ceiling!

Rolf and his two companions remained frozen in place, staring dumbfounded at the wooden door that had nearly been smashed to pieces, not daring to even breathe for a long time.

Gavin Dust off his robe and smiled with satisfaction.

This is my world.

I am the King of Fire—uh, the King of Hogwarts!

Then, he looked thoughtfully at the tightly closed wooden door.

Judging from Snape's expression, going to him now would most likely be fruitless.

We need to find a reason that forces him to speak.

Surely we can't really sneak into Snape's room at night?

At 2 PM, in an abandoned Potions- making room on the west side of the Third Floor the castle.

A sheet of Parchment with preparation instructions written on it was spread out on one corner of the worktable:

[I. Preparation: Slowly boil mature, Fluxweed in distilled dew... After settling, add the sloughed African Tree Snakes one by one until the snakeskin dissolves completely, revealing silvery scales on the surface of the medicine.]

[II. Dividing the Pots: Divide the medicinal base into two pots, add the left and right horn powders of the same Bicorn to each pot, and stir simultaneously in a clockwise and counterclockwise direction... When the two horns of the herb are separated into silver-white and dark gray colors, place the Knotgrass horizontally into the two pots and immerse them until transparent liquid beads seep out from the central grass knot...]

At this moment, on the Knotgrass knots spanning between the two auxiliary pots, a drop of transparent liquid is just about to drip.

"Combined medicine."

Cordelia and Gavin simultaneously raised their hands and poured the silver-white and dark gray liquids back into the main pot.

The two streams of liquid collided and instantly transformed into two opposing, rotating streams—one silver and one gray—that chased, collided, and bounced away rapidly along the inner wall of the crucible.

Gavin decisively extinguished the flames under the crucible, picked up a pinch of finely ground Moonstone Powder with his right hand, held it above the rim of the pot, and stared intently at the rapidly spinning two-colored vortex inside.

Just as the two thin streams of silver and dark gray first met simultaneously in the very center of the pot—

Moonstone Powder scattered instantly!

Buzz!

The violently churning vortex inside the crucible suddenly stopped.

The two distinct streams of medicine, one black and one white, merged instantly under the control of the Moonstone Powder, transforming into a pot of even, warm, pearly-gray liquid. A layer of clear silver light briefly appeared on the surface of the liquid before it returned to calm.

The Biphasic Transformation Potion is complete.

Although the formula is very similar to Polyjuice Potion, this doesn't require as long to prepare; it only takes a few hours.

Gavin picked up a flat, colorless Crystal Bottle and carefully poured the cooled medicine into it.

Gently shake the bottle, and a fleeting silver line will be left in the pearly gray liquid.

Just as Gavin tightened the cork, Cordelia turned her head and curiously examined the Crystal Bottle in his hand:

"This is the Potions you were talking about, the one that can change your gender?"

Gavin nodded. "It should last for twelve hours, that should be enough."

Cordelia stared at the pearly gray liquid for two seconds, thought for a moment, and then reached out her hand to him:

"Give it to me, I'll drug him."

Gavin paused, hesitating slightly. "If this gets discovered, you'll be put in solitary confinement."

Cordelia scoffed, her silver-gray eyes filled with disdain:

"I remember everything he's done for you these past few weeks—how he's cursed you behind your back, how he's torn up Hermione's letter in the Great Hall, how he's bullied her. It's time he paid the price!"

Gavin held the medicine bottle, still somewhat hesitant.

Cordelia looked up and silently glanced at him:

"Don't forget, who's the client now."

Gavin gave up, sighed helplessly, and had no choice but to place the Crystal Bottle in her palm.

Cordelia smiled with satisfaction, took out a delicate velvet pouch from inside her Robes, and pulled open the drawstring to put the Crystal Bottle inside.

Just as the bag was opened, Gavin's gaze inadvertently swept across the opening—

He could clearly see that another small glass medicine bottle was already quietly lying inside the velvet pouch.

With the light streaming in from the window, he immediately noticed the extremely peculiar color of the liquid in the bottle.

Gavin's eyelids twitched. "What's that?"

"That one?"

Cordelia calmly inserted the Biphasic Transformation Potion, tightened the drawstring again, and spoke as casually as if she were discussing the weather:

"That's also punishment for Malfoy."

Gavin stared at her in shock. "Isn't one bottle of Gender-Change Potions enough?"

"Of course not."

Cordelia raised her chin as if it were perfectly natural:

"That's your plan, and I have mine. Now we can put them together."

Gavin paused for a moment, then, driven by his meticulous instincts, couldn't help but ask another question:

"Wait, are you sure these two Potions won't interfere with each other and affect their efficacy when mixed together?"

Who said I was going to mix them together?

Cordelia glanced at him with an expression of disbelief, and said slowly and deliberately:

"I've heard Pansy mention at least ten times in the lounge that Malfoy eats a scone and a cup of hot Earl Black Tea every evening before dinner. I would put the two bottles of medicine separately into his scone and his Black Tea."

"I mean, what happens after it's ingested?" Gavin was still curious. "With two drugs taking effect one after the other, what if they counteract each other in the stomach?"

Cordelia tied the velvet knot on her small bag and said calmly:

"According to Golpalott's Second Law, when Potions that have already been extinguished and set meet within the body, they will only affect each other or have their effects combined. Looking at the main ingredients on both sides, they are not incompatible, so there is no danger to life."

Gavin raised an eyebrow. "Are you sure?"

Cordelia paused, instinctively puffing out her chest, her silver-gray eyes narrowing dangerously.

"What, are you questioning my Potions?"

Gavin thought for a moment, then honestly shook his head.

To be fair, Cordelia's talent in Potions was indeed extremely high. Not only had she already mastered the advanced Potions Class on her own, but Snape would also give her extra tutoring.

She said there was no danger to life, so no one would die.

However, Gavin still had some concerns:

"You won't die... but aren't you worried at all that these two things colliding might cause any other side effects?"

Cordelia turned her head, a barely perceptible curve appearing at the corners of her lips:

"Wouldn't that be perfect for Mr. Malfoy to test it out for us?"

Gavin's lips twitched.

He silently reminded himself that even if the sky were to fall, he must never easily offend this young master of the Rowle family.

The young lady's flesh is black when cut open.

Cordelia carefully tucked the velvet pouch into her body before turning around, looking at Gavin with a curious gaze:

"But where did you learn such a strange Potions? You still haven't told me where your soul went while you were unconscious for so many days."

Gavin met her gaze, smiled, and then looked out the window at the gray clouds of the overcast sky.

That's a very long story.