I Laid a Phoenix Egg, but My Sister Swapped It for a Rotten Egg

My older sister and I were princesses of the Featherfolk, and both of us had been chosen by the Phoenix Lord as candidates for Phoenix Queen. In my previous life, we gave birth on the same day. I laid a fire phoenix egg, while she laid a rotten one. Afraid her affair would be exposed, my sister switched her rotten egg for my fire phoenix egg on the day we gave birth. She was honored as Phoenix Queen and basked in unparalleled glory. Meanwhile, I was accused of adultery, had my tendons torn out and bones scraped clean, then was thrown into the endless void to die. In a daze, a little bundle wrapped in flames told me that he was my child. When I opened my eyes again, I was back on the day the fire phoenix egg hatched.