Daughter of Fortune

Two sisters die and wake again at an earlier point in their own lives. Shen Nanqiao, the legitimate elder daughter, remembers exactly how the palace destroyed her, and she arranges for Shen Zhinian to be sent there in her place. Zhinian arrives in the inner court with no allies and a rank low enough that nobody bothers to hide their contempt. She spends her first months learning who reports to whom, which consorts are backed by which ministers, and what each of them wants badly enough to be careless about. Then she starts using it. Every move she makes is worked out in advance and aimed at someone specific, and she keeps winning quietly enough that it takes a while for anyone to trace the losses back to her. Emperor Nangong Xuanyu notices before the others do. He tests her, she tests him back, and neither is willing to say what they actually think for a long stretch. The court outside the palace walls has its own plots running, and they reach the throne itself. By the time that happens the two of them have stopped circling each other and are working the same side.