The Radiant Curse by Elizabeth Lim

Channi was not born a monster. But when her own father offers her in sacrifice to the Demon Witch, she is forever changed. Cursed with a serpent’s face, Channi is the exact opposite of her beautiful sister, Vanna—the only person in the village who looks at Channi and doesn’t see a monster. The only person she loves and trusts.
Now seventeen, Vanna is to be married off in a vulgar contest that will enrich the coffers of the village leaders. Only Channi, who’s had to rely on her strength and cunning all these years, can defend her sister against the cruelest of the suitors. But in doing so, she becomes the target of his wrath—launching a grisly battle royale, a quest over land and sea, a romance between sworn enemies, and a choice that will strain Channi’s heart to its breaking point.
Weaving together elements of The Selection and Ember in the Ashes with classic tales like Beauty and the Beast, Helen of Troy, and Asian folklore, Elizabeth Lim is at the absolute top of her game in this thrilling yet heart-wrenching fantasy that explores the dark side of beauty and the deepest bonds of sisterhood.

ISBN: 9780593710029