Forest of a thousand lanterns - Julie C. Dao

Eighteen-year-old Xifeng is beautiful. The stars say she is destined for greatness, that she is meant to be Empress of Feng Lu. But only if she embraces the darkness within her. Growing up as a peasant in a forgotten village on the edge of the map, Xifeng longs to fulfill the destiny promised to her by her cruel aunt, the witch Guma, who has read the cards and seen glimmers of Xifeng's majestic future. But is the price of the throne too high?