Seven Ways to Kill a King — Melissa Wright

She was born a princess. They made her an assassin.One was an accident. Two a coincidence. By three, they would know. It would be harder, but I would avenge my mother's death. These kings would pay that price.Seven cities make up the Storm Queen's Realm, each of their self-crowned, murderous kings are one of Princess Myrina's marks. The treasonous curs may have banded together to share a stolen throne, but soon they will fall.They thought her dead, killed in the massacre. They thought their rule secure, but Myrina of Stormskeep has awoken. With the help of her loyal bloodsworn, the shadow princess will have her revenge.