All Hail the Spirit Emperor

Seeking a heavenly title, a 500-year-old weasel spirit is crowned by a dying emperor and vows to rule well. Wish-bound magic lets him slay a poison consort, thunder at corrupt ministers, foil drought and plague coups, save the realm with dragon blood, defeat invaders, purge traitors, give 13 years of peace, pass on the throne, and ascend.