"The shrewd and powerful Slytherin comes from that quagmire"
"Maybe you will enter Slytherin, maybe you will make sincere friends here, but those cunning and insidious people will use any means to achieve their goals."
It is said that a few years after the founding of Hogwarts, Salazar Slytherin, the founder of Salazar Slytherin, built the Chamber of Secrets in the school and eventually left the school.
It is said that he left after being driven away by the other three founders...
After leaving, Salazar made mistakes when drawing the alchemical circle due to excessive grief and anger...
So, Salazar Slytherin became Harry Potter...