The Duke's legitimate daughter Cecilia awakens the number 999 Faceless Mortal Seal, considered a waste seal, gets dumped by the crown prince, and is exiled to the Abyss class holding heavy criminals. She unlocks the ancient divine magic weapon Change-Thousand, subdues a group of crazy partners, fights against the royal family and the holy see, breaks through the bloody battles of the league, and fights against the invading outer gods from beyond the sky. Breaking free from the lifespan curse, overthrowing the corrupt old order, breaking the shackles of birth, and finally becoming the dark night queen ruling the rules of the continent.