How to kill a person in a person?

It's very simple. The method described in the video at the link below allows you to replace the personality of a person with the personality of a fly agaric, since a person's personality is much weaker than a fly agaric. But it's not a fact that the new personality of this person (fly agaric) will appeal to you much more than the last one. The last time this happened 100 years ago and the consequences were worldwide. Video link https://youtu.be/wmEFusVe29g

An ambiguous question, so I will give an ambiguous answer.

By personality I mean a person who has formed his own outlook on life. And I'm not talking about VK status, attitude to alcohol and religion. And not about the herd, which is stamped from childhood, they say, Study Well-Step On The Budget At The University-Do Not Smoke-Do Not Consume-Work On Uninteresting Work-Buy An Apartment Vipoteku-Give birth to children and blablabla
This, of course, is a cool example. But if a person only knows this in life, all these "commandments", why the hell is it to be considered his personality?))
So I ask this - why for the budget and for the university? And he told me - well, that's right, they told me so, that's how everyone does, it's reasonable.
But after all, not everyone is capable of this, and even more so not everyone wants this for himself.
I respect non-standard people, owners of a "new look", so to speak. With whom even in an argument, even a polemic, even a discussion. They have read, seen enough, heard enough. Have absorbed sweet nectar and crave even more.
They are already Personalities, and if they kill such people, then only physically.
And many, as they were not personalities, will not become them. So they say: they suppress the personality. But how to suppress it, because it simply does not exist ?!))

Elementary you can. Constant suggestion that he is insignificant, conviction of his own wretchedness, stupidity, uselessness, this can be long years of persecution, ignoring those people who are dear to a person, it can be a strong psychological trauma, shock, as a result of which personality decay can begin. This is partly a defense mechanism. For example, rape of a child can lead to a similar outcome.

Personality is a set of qualities of an individual, expressed in social relations.

And if a person suddenly became an asshole, then something has changed in his personality, but he has not ceased to be a person (for fans of "Game of Thrones" : how the personality of Theon Greyjoy clearly changed after some procedure, but remained a personality, because he remained the subject of social relations).

As for killing a personality, alcoholic parents do an excellent job of it, which I leave their children at an early age to be raised by animals or simply socially isolated. This is how Mowgli children grow up.

Mowgli children do not have social behavior skills, therefore they cannot be a subject of social relations, which means they are not a person.

Absolutely anyone, the only difference is in the time and effort spent on it. Every person has a weak point, no matter how carefully he conceals it.