Shadow Princess by Caroline Peckham and Susanne Valenti

The shadows are in my blood.

I can feel them crawling through me, slithering under my skin and taking me hostage. But the darkness within me isn't nearly as bad as the darkness that lives around me.

The four Celestial Heirs will stop at nothing to destroy the lives of me and my sister. But they haven't figured out yet, that we're the strongest creatures they've ever known.

And when that secret comes out, we need to be ready to face them as well as any other cruel Fae who rises against us.

It’s us or them. And it damn well won’t be us.