When An Extra Lives

In the Solareon empire, mana flows through every living being. Unfortunately, Audrey awakens inside the frail body of a young noble girl named Adriana Astrielle, the sickly side character from a novel entitled, Bound by the Divine Light.

In the original story, no one ever discovered the true cause of her sickness nor the cure, not even the male lead. Adriana's role was simply to be a driving force for the male lead to meet the female lead.

Although Adriana's mother was friends with the Grand Duchess, the connection between their families was never extended to their child, Adriana and Lucien Solivar, the Grand Duke's heir. They were merely acquaintances in name-two children who occasionally crossed paths at formal events, exchanging polite nods but nothing more.
To Lucien, Adriana was just another noble girl he barely remembered.
And in the original timeline, he never knew why she was constantly ill. He never learned the truth behind her weakening mana core, never realized she needed him to survive. Their paths simply never intertwined deeply enough for him to find out- not until after she died.

But Audrey knows everything.

She knows that Lucien is the only one capable of stabilizing Adriana's condition. She knows that if she doesn't reach him soon, the body she now inhabits will eventually die.