The Voyant and the Mark of Malice by Sadie Hewitt

He may be clever, but she’s already a step ahead…
Kalia Salam is a Voyant, or a person with the ability to create mind-altering visions and project them into others. But when the punishment for having that ability is death, every decision becomes a strategic calculation to avoid execution. Unfortunately, that includes tethering herself to the continent’s most wealthy brothel owner and only using her magic to pad the madam’s pockets. That is, at least, until she needs it to protect those around her. But when Kalia uses her magic on the wrong client and is mistaken for a powerful djinn, one that the pirates have been meticulously hunting, she becomes ensnared in her most complex game of deception yet. Because, one way or another, she refuses to fall to the hands of a cursed captain.
Captain Rahmi Abada revels in collecting dying souls from the sea, particularly those burdened by guilt. But whispers of a tale have begun to swirl…a tale about a mysterious gemstone with innumerable abilities, including the power to shatter any magical bond. Consumed with the idea of sailing for eternity without his binding curse to Liddros, God of Sea, Rahmi enlists the help of the fiery djinn he forced aboard his ship. The only problem? The djinn harbors her own secrets, ones that threaten to unravel Rahmi’s carefully laid plans.