After a Failed Mission, I Was Imprisoned by the Yandere Villain

I was transported into a novel, and my mission was to stop the villain from turning evil. The System said that if I made him feel love and warmth, I could redeem him. For ten years, I stayed by his side, becoming the only light in his dark world. I thought I had succeeded, because he seemed so normal, even treating me with tenderness and care. Then the System announced that the mission had failed and prepared to erase me. I closed my eyes and waited for death. When I opened them again, I saw his blood-red eyes. He crushed the System's glowing orb and locked me in a golden cage. "Big Sister," he murmured with a smile, stroking my face. "Were you trying to redeem me, or were you trying to leave me?"