My Matchmaker from Hell

A clerical error in the underworld gets the wrong soul pulled in. Su Ruanruan is an ordinary office worker whose whole ambition was to be left alone, and now she is standing in front of the King of Hell over a paperwork mistake. She beats him up. What she gets out of the encounter is a rebirth package with a system attached, and a placement in an imperial harem, which is not what she asked for. The King of Hell's arrangement requires her to get into the emperor's bed and hold his attention. The system carries her through the parts she has no training for. She takes apart the women scheming around her, goes up against the cruel consorts, gets corrupt officials punished, and ends up defending the country. She starts at the bottom of the palace staff, the lowest rank of maid, and climbs, speaking for every overworked underling in the palace and out of it against rules stacked to keep them down. By the end her standing is that of a saintess, level with the emperor himself, and the thing she wanted all along, a life with nothing demanded of her, is finally within reach.