Oujo Denka wa Oikari no You desu

A princess known for her unmatched magical abilities and widespread affection loses her life amid an unending war that destroys her kingdom, family, and loved ones. She awakens a thousand years later in a new era, reborn into the body of Dorossel, a lazy and ineffective individual. Now despised by her family and fiancé, she grapples with the unfamiliar world and the changes that have occurred since her death. She is particularly frustrated by the decline in magical power in this new time.