Ivan did not notice Ron's abnormality, but an incident that caught him off guard woke him up and he realized that he had been too immersed in the study of the Dark Arts recently.
Such behavior was extremely dangerous and just plain wrong.
So he changed his research topics, focusing more on analyzing the principles of magic, using dark magic as supplementary knowledge that needed to be understood as a starting point, to study the principles and structure of magic, involving many theories and so on.
In his further study, Ivan's use of the magical principles described in the magic books was more to increase his strength, rather than trying to use the previously recorded dark magic.
Although this hindered his research and forced him to get more magic books, it essentially prevented Ivan from becoming a dark magician.
Last year, Tom Riddle's diary had tempted Ivan to practice and use the Dark Arts frequently, in the hope that he could give himself over to the power of the force.
Since then, Ivan had realized that the excessive use of dark magic could make the wizard's soul evil and unstable. With the use of black magic, there would be many cruel thoughts in the heart, and a person could even change completely.
In recent research, knowledge gained from many ancient magic books also confirmed Ivan's initial conjecture.
Although the magic world had not yet reached a consensus on the source of magic, but while magic comes through blood, the essence of the magic spell depends on the power of the spirit and soul, this theory has been increasingly recognized by magicians.
In addition to the magician's magical power, the source of power and the size of black magic depend mainly on whether the user is bad enough.
Using Black Magic for a long time will gradually make a magician evil.
Ivan had no such intentions. His purpose in studying Dark Magic was to increase his own strength, to gain a deeper and fuller understanding of dark wizards, to understand Voldemort, to know the enemy he was about to face. He never wanted to become an evil dark wizard.
Therefore, after making sure of that, he hastily changed his research topics.
Ivan destroyed his previous research notes, which led to the fact that Ron, who had been secretly researching, found nothing. He had stolen many of Ivan's things, but was never able to find the notebook he had seen with the horrible design.
Although no evidence was found, his opinions of Ivan were getting weirder and weirder.
After a brief confusion, Ron felt a strange anger. He thought Ivan had discovered that he was investigating him, so he had destroyed all evidence of his research into dark magic.
Ivan did not notice Ron's anomaly. What really woke him up was related to the so-called War of the Houses.
Gryffindor and Slytherin didn't fight due to the strengthening of management in the castle, but there was some friction. Snape and Sirius didn't take a good advantage in that either, and Malfoy practically came every day to provoke them as the Quidditch match, which was to decide this year's school cup champion, was approaching.
This situation continued until the Sirius Dueling Club was reinstated.
Shortly after the Ravenclaw and Slytherin Quidditch match, Sirius' proposal to resume the dueling club was plastered on the notice board.
Unsurprisingly, this was unanimously welcomed by the young wizards of the school.
Although the Dueling Club that Lockhart organized last year turned out to be a joke, Sirius was recognized as strong and powerful. Everyone was excited about the idea of being able to learn dueling skills and curses with him.
Even more anticipated than the re-establishment of the Dueling Club itself was the duel between Sirius and Snape, which had become a hot topic at school, and there had been much debate over who was the stronger of the two.
Unfortunately, Snape did not show up at the first Dueling Club meeting.
Due to Dumbledore's intervention, both Snape and Sirius were heavily restrained.
Although both parties did not hide their dislike and resentment against each other, at least they did not have a duel or "tit-for-tat" in front of the students as before.
At the Sirius-led Dueling Club, Snape did not show up, and Sirius asked Professor Flitwick to become his opponent.
The event was fairly normal at first and went off without a hitch. Everyone learned about dueling etiquette, Professor Flitwick explained various spells that were more common in dueling, and Sirius also taught them some of his combat experience.
For Ivan, the spells might be a bit low level, but other younger wizards, many of them seniors, were still very interested and learned with great interest.
That was not surprising. Hogwarts had never taught young wizards any knowledge related to dueling. The Defense Against the Dark Arts class, which should be the main assignment, was also terrible. The teachers of the Defense Against the Dark Arts class changed every year, including disreputable wizards like Lockhart, or unscrupulous types like Quirrell.
Their teaching methods were also very different, and it was difficult for young wizards to learn systematically and thoroughly how to resist the dark magic in their courses.
Most young wizards were self-taught in the spells associated with Dueling and defense against Dark Magic.
They were more interested in prank magic than in the usual spells and charms.
True, these magic spells could have an unexpected effect in battle, but their effectiveness was not comparable to the standard dueling spells commonly used.
Sirius' club was an unprecedented success, and the dueling skills he and Professor Flitwick demonstrated were a great success.
Before the group practice, everything was going very well. But then the situation began to take a turn for the worse, either intentionally or inadvertently; Sirius matched many Gryffindor and Slytherin students in group practice.
Ivan's opponent was a second year boy he couldn't remember the name of. The boy seemed to want to use a curse against him. However, when he had not yet raised his wand, Ivan had sent it flying far out of his hand.
He looked at Ivan with astonished eyes and could not believe what was happening in front of him. Although Ivan was very famous, before the test, he didn't think that his strength was much worse than Ivan's. He was the strongest among the second year Slytherin students.
Instead of preparing to use his wand attacks and defensive spells as Sirius said, he was thinking about teaching Ivan a hard lesson and embarrassing him in front of the whole school.
Ivan had no idea of the Slytherin student's thoughts in front of him, and he had no interest in doing naive magic practice on him.
He had been analyzing his duel with Snape. With research and mastery of dark magic and other magical theories, his recent magical power had advanced by leaps and bounds.
Ivan believed he could hold his own against Snape longer. And if his magic was strong enough, it was not impossible to counter him to some extent.
In this case, the strength of this guy in front of him was completely inadequate.
Ivan then had a deeper understanding of his wand and felt more comfortable using it, almost instantly.
He wasn't sure what his opponent intended, so he just settled the fight as quickly as possible.