Tensei shita Daiseijo wa, Seijo de Aru Koto wo Hitakakusu

Fia has always wanted to become a knight despite being the least gifted member of her martial family. During a test that puts a dragon in her path instead of the minor demon she expected, a mortal wound unlocks memories of another life: she was once a Great Saint who defeated the Demon King and ultimately died because of what she was. Her healing and protective magic returns with those memories, along with a clear understanding of what discovery could cost her. Fia chooses a difficult compromise: continue training openly as a knight, use the Saint's power only when she cannot stand aside, and make certain no one realizes who has been reborn.