I'm Just a Supporting Female Character

A supporting female character's memoir. Upcoming historical romance "After Transmigrating as a Cannon Fodder Assassin" When other people turned eighteen, they wore formal dresses, camisoles, and high heels. Zhan Yun was different: she transmigrated into a book, and not just any book, but an old-fashioned political intrigue novel set in ancient times. As luck would have it, she wasn't the heroine, blessed with a halo and boundless powers. She wasn't even a white lotus, black lotus, or green tea supporting character. She was an assassin. An assassin who pretended to surrender, only to make a failed attempt on someone's life, and whose story ended as soon as she appeared. Remembering the story's opening, where the assassin was hacked to death in the court and left exposed for days, Zhan Yun stared wide-eyed at the head that was fated to be claimed by the male lead. Then she twisted the wrist holding her poisoned blade "The horse-riding man is so brave and mighty..." After hopping through an entire square-dance routine with her left and right feet out of sync, Zhan Yun knelt and held up her blade, her expression perfectly serious. "This humble one comes by the Crown Prince's command to offer Your Majesty a secret technique for self-defense: After-meal blade-waving, a hundred-step dance. In time, you can become a complete fool." Question: "What does 'complete fool' mean?" Zhan Yun kept a straight face. "A genius unmatched in the world, whose accomplishments surpass the Three Sovereigns and whose virtue shines upon the Five Emperors." - Much later, the man took Zhan Yun's hand and climbed the city tower. Gazing out over the vast realm, he was overcome with emotion. "A Yun, you're the real fool here." Zhan Yun: "..." "I Insult Myself"; "The King Is a Beautiful, Strong, Tragic Soul, but Unfortunately He's the Villain"; "After Transmigrating as a Cannon Fodder Assassin, I Accidentally Ended Up with the Villain I Was Supposed to Kill"; "My Other Half Is So Short-Lived, and I Have to Die with Him. What Should I Do?"; "Then I'll Find a Way for Us to Cheat Our Way Through, Take Down the Protagonist, and Become Masters of Our Own Fate" Theme: Born in hardship, die in comfort