Kill the Male Lead to Become the Demoness

After the 16th play-through, Qianqiu finally realized that the world she was living in was just a game. However, she was not the heroine, but just the female support character, destined to always be the loser. Tired of being stuck in an endless loop, she decided to break free from the game's plot. However, in the process of doing so, the protagonist also started to act strangely? (Source: Kuaikan, translated) *Note: An entry in the 2021 Kuaikan Tiaoman Contest*