The Ghost General's Revenge

Underworld Adjudicator Jocelyn discovers her descendant Claire persecuted by a fake heiress. Enraged, she returns in Claire's body for one month. With disguised Crown Prince Adrian, she protects her granddaughter (a puppy). She cleans up the Shaw family, dealing with the fake heiress, brother, and parents. She and Adrian expose the Second Prince's conspiracy, quelling court turmoil. After a month, Jocelyn returns to the Underworld. Adrian pursues her, offering the empire as a betrothal gift.