The Assassin's Curse Series
Cassandra Rose Clarke
Ananna of the Tanarau abandons ship when her parents try to marry her off to another pirate clan. But that only prompts the scorned clan to send an assassin after her. When Ananna faces him down one night, armed with magic she doesn't really know how to use, she accidentally activates a curse binding them together.
To break the spell, Ananna and the assassin must complete three impossible tasks—all while grappling with evil wizards, floating islands, haughty manticores, runaway nobility, strange magic... and the growing romantic tension between them.