Shiro Shion thought she was an ordinary person, until she was 18 years old, something claiming to be a system appeared in her mind and told her that the world she existed in was just a comic book. She was the last villain in the book. She ended up being defeated by the protagonist group, betrayed by everyone, and her two young tamers would also die violently in a few years. In order to change her destiny, she signed a contract with the system.
The worlds I want to write about at the moment: Magic Returns, Prince of Tennis, Volleyball Boy, Kuroko's Basketball, Detective Conan...