Idea: MC is, like almost every novel, born with a System. [He/She] develops quickly, and the system begins to show drawbacks. [His/Her] Qi begins turning more toward the [feminine/masculine] side, appearance following suite. A Mythical Hero decides to travel the country side, saving their village from a [Ultimate Grade Beast] and saving the day, falling in love with the MC, not knowing [His/Her] true gender, as everything about them changed.