Reincarnated as the Most Hated Sovereign

Adrian, known as the most dangerous assassin and mafia lord, died due to an ambush. In an unexpected turn of events, he is reincarnated into the body of the most hated Sovereign. The Sovereign, known as a sweet and loving person, is despised by everyone. What will happen if the person known as the most hated Sovereign becomes cold and merciless because Adrian is reincarnated into the body of the most hated Sovereign?"

"I apologize if my grammar isn't perfect. This is my first time writing a story especially English so I hope you can understand as English is not my first language and I'm not fluent in it. Please no hate