Camellias

Jiang Yukui's sister is alive. She is the one who has spent years laying a plan under the throne, and the two of them being twins is part of how she has done it. Jiang Yukui knows none of this. She is the Holy Maiden of the Zhao Tribe and she spends her childhood shut in a cell, and when word comes that her sister has been killed she goes out after the people she holds responsible, carrying the Siming power. Feng Ye takes her into his household. He holds more at court than his title accounts for, the two of them watch each other for a while, and then they stop watching each other and move against the emperor and the empress together. She learns what her sister is while she and Feng Ye are still in the middle of that, and the work she has done since the cell turns out to have been useful to her sister.