From Azkaban to Hogwarts.

The strength of a spell depends not only on understanding its characteristics and proficiency in casting it, but also on the wizard's own magical power. He was actually at a disadvantage when fighting a seventh-grade student.

"Go this way—there's a secret passage leading directly to the fifth floor."

Harry quickly determined his direction, activated the Iron Man Charm, and headed straight for the secret passage—the one the twins had pointed out to him earlier, so he wasn't sure if there were any more ambushes inside, or if the danger might even come from the twins themselves…

But the external traps are indeed a bit too much – this doesn't seem like the style of difficulty the professor set. There's no hope of clearing it all out; who knows if more people will join forces to attack.

"Over here..."

Harry cautiously observed his surroundings, while also keeping an eye out for the twins who might suddenly appear.

But the journey was uneventful—when he led Hermione and Ron to the finish line, he was so relieved he could hardly believe it.

"But what about the professor? What about the twin brothers?"

-

"Are you really not going to block them anymore?"

"Why are we still blocking it? We need to find a place to hide him!"

George looked at the bag in his hand—they had gotten their hands on a magical bag while the professor and Peeves were locked in a fierce battle. Although it seemed to be unable to do anything at the moment, the initials of Gryffindor on the bag were enough to explain it.

Just like when they got that map back then, the two of them decisively took good care of the good stuff.

They've always had a knack for magical items—whether it's making them, identifying them, or even distinguishing them from a pile of junk, anything they deem remarkable is truly amazing, and they've almost never made a mistake.

"Merlin's stockings, did they really come from Gryffindor?"

Fred stared at the cloth bag, utterly unable to believe it—Peeves had hidden such a treasure, and yet they'd taken it?

"But it looks so new, it even seems a bit unfinished..."

"That's not necessarily true—look at the Sorting Hat, it claims to be Gryffindor's hat, but isn't it just like that?"

The two were talking about topics that could easily provoke a certain hat, but their eyes were always on the bag. "There are still some Galleons inside. Hopefully, it's not just an ordinary money bag."

“If it were just a regular purse, I would return it to the owner—but I just don’t feel like it is.”

"Perhaps you are right, Fred."

George shook his purse. "We'll be able to figure it out soon. We're probably the only students who've stolen Pippi's stuff in the last few years, right?"

"Maybe? I guess the professor beat Peeves so badly he doesn't even remember him anymore, but our solitary confinement will probably be..."

He spread his hands, his tone completely calm—he was used to it.

-

"Another one..."

William waved his wand and carried the students to a corner—these seventh-graders were a bit cunning; setting traps and misleading others was one thing, and throwing dung balls was also understandable, but weren't it a bit much for seventh-graders to hide and launch a sneak attack?

Through his tireless efforts, the traps finally became somewhat more plausible—he eliminated the seventh-grade attackers, added some traps, and increased the difficulty of some of them…

After doing all this, William walked along the outer wall of the castle directly to the fifth floor—he had no choice; otherwise, he wouldn't have enough time to clean up the competition area.

When he arrived at the finish line, as he expected, Harry had already reached the end with his two friends.

“You played better than I expected, Harry.”

William nodded to Harry, his smile impossible to suppress.

"Ronald, although as a professor I shouldn't be discussing these things, haven't you forgotten something?"

When William turned his gaze to Ron, he offered a curt, emotionless remark.

Ron's face tensed up instantly, and he rushed downstairs without looking back.

To this, William could only shake his head kindly and say nothing—Harry was with you on the way here, and I hope you can clear the way back, after all, those training sessions related to curses weren't for nothing.

Watching Ron run off into the distance, Harry almost burst out laughing. He'd clearly thought about the trap—but wasn't it safe now?

But he soon stopped laughing.

"Harry, please compile the student grades for each house and come to my office to report later."

William nodded. "By the way, Gryffindor gets fifteen points first."

"I'm going to see Professor Moody and ask him to make sure the seventh graders get the hallway back in order and do their jobs properly!"

He waved and walked toward the main office.

-

"It's almost done. Some people are repairing the corridors, and others are being put in solitary confinement—I should start thinking about this now."

In his office, William, fully prepared, began to explore the shoes he had obtained from Peeves.

He always felt that Pippi had a secret, and these shoes today were a good example of that.

But this thing can't be forced, nor can it be studied in depth—a principal plus a bunch of professors have already become Pippi Ghost's glorious achievements, so he felt that he didn't need to boost Pippi Ghost's record anymore.

These shoes were a pleasant surprise; I'll definitely check them carefully before using them.

'The linen material is very rough. But it's not impossible to make it by wrapping it around dragon skin and adding a lining; it's not in a final, unfinished state, just in a usable condition…'

'Like the legendary sword of Gryffindor—it's said to still grow according to what it cuts…'

William examined the shoes. They weren't as outrageous as the legendary props, but they were definitely not bad either.

'No hidden curses, no other magical artifacts embedded…'

'All materials, including the nails, have been inspected; you can try it on now…'

William checked that it was safe again before carefully putting the linen boots on his feet.

A strange feeling suddenly arose—just like he had felt before, he could now Apparate freely within the castle.

Moreover, the school's protective forces, which they had encountered during the Triwizard Tournament's maze phase, were clearer than before, only slightly isolated by some inexplicable forces.

"Strange, so strange..."

William drew his wand, summoned a whole piece of chocolate, and then tapped it.

The next moment, it appeared directly on the other side of the table.

William's eyes widened as he began to tear open the chocolate's wrapper—a dozen seconds later, he stared at it in astonishment.

Not a single scratch or dent; yes, perfectly intact.

He was using a variant of Apparition, which simply used the power of Apparition to teleport items over short distances. Logically, under the protection of Hogwarts, the chocolate should have either turned into powder or melted, not remained intact.

"Does it really work?"

He looked at the chocolate curiously, then removed the protective gear.

Next came the exciting live animal experiments.

He's going to the Forbidden Forest to find a lucky rabbit, or maybe Hagrid's rooster that's lucky enough.

-

"Insect experiment passed."

"Animal experiments passed."

"The magical creature experiment has passed."

"Potion experiment passed."

……

William stopped apparating the last object in his hand—it was almost certain that he could now apparate within the school grounds as long as he was close enough to the shoe.

Moreover, it seems to be more than that—William's tests outside of school showed that it could even apparate more precisely and from a greater distance.

"Let me start by testing a simple intra-school teleportation..."

"If it's feasible, perhaps I can try Apparition in Animagus form again... This might be one of the breakthroughs..."

Chapter 557 A New Understanding

"Human transformation..."

William's office was now piled high with materials related to Transfiguration—after that audacious idea came to him, he was determined to try Animagus Transfiguration combined with Apparition.

But this is not a problem that a pair of shoes can make up for. He must take his shapeshifting skills to the next level and completely master the most difficult human shapeshifting before he can try this dangerous superimposed magic state.

Magic is actually quite complex; it's not that mastering a spell instantly makes you a master—even black magic, which is generally considered relatively easy to learn, has extremely strong constraints, let alone other spells.

Yes—dark magic is easier to learn.

Although many wizards do not agree with this view, this is William's opinion.

Even a fourth-grade student could potentially master the Avada Kedavra curse—but what good would it do? They couldn't even kill a rooster with the spell.

In William's view, to learn black magic, one must first understand evil curses and their harmfulness to wizards, so that one can reveal one's malice in the casting of black magic.

Next, we need to understand curses—the unyielding power of curses is an important component of the almost irreversible damage caused by black magic. In some cases, curses, due to their purity and unpredictability, can even surpass black magic.

Okay, once you've grasped and understood all of this, you need to learn how to control dark magic—pouring malice and hatred into your magic, and then adding sufficiently skillful incantations. Only then will your dark magic have offensive and lethal power, without causing too much harm to yourself.

Yes, apart from pure dark wizards, other wizards who use dark magic will suffer negative consequences for themselves. The more powerful the dark magic, the greater the damage it will cause to themselves. This is what happens when one rashly uses the power of emotions and malice; it harms the enemy while also harming oneself.

Finally, and most importantly, you must learn how to dispel the spell before using it, otherwise you may be harmed by your own spell.

Even so, dark magic is the easiest spell to learn in the entire magic system—because other spells are too difficult, while the prerequisites for dark magic are actually very easy to meet if you are determined.

Not to mention the geniuses in this field—whether innate or acquired.

Because both the malice of a curse and the cruelty of emotions can be cultivated in life, unlike other spells that require one to learn little by little and forcibly elevate oneself to that level.

Even the Animagus, which William suspected of cheating, actually had incredibly high entry requirements.

Putting aside the tediousness of collecting materials and the patience and luck required to complete the ritual, just understanding the Animagus transformation is enough to stump most wizards—it requires a strong foundation in transfiguration, an excellent teacher or an absurdly powerful understanding, and considerable courage, all of which are indispensable.

Only after fulfilling these requirements can one hope to use this cheating tool.

Then there's the Spellcasting course—the techniques of casting spells, the understanding of incantations, and the vast knowledge system. If you're missing even one of these, you'll be stuck and have to slowly grind it out. Even if you complete all of them, there's still combat talent and your personal understanding of incantations waiting for you. Otherwise, you'll be biting off more than you can chew, knowing a little bit of everything but mastering nothing.

As for self-defense magic—of all the schools of magic, this is the most talent-dependent. It requires not only superb spellcasting talent but also outstanding combat talent. Otherwise, there wouldn't have been the absurd situation where several seventh-year students were beaten down by Harry and his two friends, who were fifth-year students…

This was William's understanding of the spell after mastering the Animagus—but unfortunately, he couldn't share it.

Although it seems like a long and detailed document, it involves a lot of knowledge related to black magic, so he couldn't possibly tell his students the whole learning system. At most, he could extract some knowledge that was unrelated to black magic and share it with them.