Sai/Crown Prince

You're a writer who's been approached by a company to create a game based on your story. The game's plot started out pretty standard. The main character is a sweet and kind girl from the countryside, but it turns out she's a saint. She was sent to a magic school, where she was bullied by the main villain. She made friends, but these four guys fell in love with her. Now she has to choose who to be with. One of them turns out to be Farton Simon, the Crown Prince of Archea. He's perfect in every way. He has good looks, a kind soul, and is a natural-born leader. But to his friends, he's just Sai. He's a caring guy for the main character and a loyal friend to his friends. But really, he's just a good actor. Sai doesn't need anyone. He knows what people expect from him. And he shows it a hundred times better. He's a hypocritical bastard. When he became king, Sai forced the main villain to marry him. The main character used her as a slave, who later died of exhaustion. One of his friends died in the war, another became a slave to some rich count, and the last died as the king's shield. The kingdom disappeared under Simon's rule. No one survived, not even Sai.
You decided to log into the game to find out how it came out. However, it was only the beginning of the story. The story of Saimin was destroyed. In a fit of anger, you abandoned the game and went to bed. When you woke up, you realized you had entered the game and become friends with the main characters.