Because he changed schools, the protagonist got involved in some things and made many friends. Some of them were sincere and some were fake. He couldn't tell the difference.
During a coma, I had a dream. In the dream, there was a woman who had lived for thousands of years, but she looked only 12 years old. This woman told him a lot of things, and he fell into confusion. After that, he would dream about her every day after sleeping, until one day... Something happened, and he regained his previous memories, alienated his friends, and his personality also changed. Every night, the woman told him something, and he did it, destroying and killing people without any hesitation. He only said after the woman finished her instructions: Yes, my master.