My Atonement, Your Prayer

When Larastina's power as a saint manifested, she was taken in as a foster daughter of a ducal family. There, rather than being bullied, she was cherished by her adoptive parents and Anastasia, who became her adoptive sister. Larastina felt a sense of déjà vu about Anastasia in some way—— ※The romantic elements are minimal ※The settings are loose/flexible