Sacrificed to Survive

I entered the story in a book and became an unloved little princess. The imposter princess who took my place is doted on, while I only think about how to survive. I met the goddess of fate, discovered the Father Emperor's twin brother, and the royal secrets began to unfold before my eyes. The fate of the world is now in my hands. It turns out that becoming a Sacrificial Offering is the key to my survival.