Vizet felt he was still very lucky. By the time he came into contact with and began studying "Sympathetic Magic," he had already conducted relatively in-depth research into the soul;
Not only that, he also had a pair of Magic Eyes, allowing him to observe wondrous places such as the "Shadow World" from a unique perspective;
And the special experience of studying the "Shadow World" could also help him better understand "Sympathetic Magic."
Even without understanding "Sympathetic Magic" through "soul research" and the "Magic Eye," it could still be studied through other types of magic;
For example, Animagus, that advanced form of Transfiguration, could be used to study the "similarity" in "Sympathetic Magic";
The animal transformed into by an Animagus was usually considered a concrete manifestation of the soul;
Take Peter Pettigrew, whose soul had already been sucked away. He had once paid the price of a finger to cast an extremely powerful Dark Magic, blowing up an entire street to cover the traces of his escape;
That finger had been lost because of Dark Magic, and since Peter Pettigrew had no means to remedy it and reshape another finger, the fact that he was "missing a finger" was directly reflected upon his soul;
When he maintained his rat Animagus form, one toe would also be missing from the rat's front paw. This was an embodiment of "similarity" in "Sympathetic Magic."
If a person mastered Animagus and also mastered the Patronus Charm, then the Corporeal Patronus that person summoned would usually be their Animagus form;
A Corporeal Patronus was also a concrete manifestation of the soul, which was what led to this situation, and it could also be considered an embodiment of "similarity" in "Sympathetic Magic."
And Voldemort wanted to truly harm Harry, so he coveted Harry's blood and