Hundred Kingdoms Series by Alexandra Christo

Princess Lira is siren royalty and the most lethal of them all. With the hearts of seventeen princes in her collection, she is revered across the sea. Until a twist of fate forces her to kill one of her own. To punish her daughter, the Sea Queen transforms Lira into the one thing they loathe most—a human. Robbed of her song, Lira has until the winter solstice to deliver Prince Elian’s heart to the Sea Queen or remain a human forever... morePrincess Lira is siren royalty and the most lethal of them all. With the hearts of seventeen princes in her collection, she is revered across the sea. Until a twist of fate forces her to kill one of her own. To punish her daughter, the Sea Queen transforms Lira into the one thing they loathe most—a human. Robbed of her song, Lira has until the winter solstice to deliver Prince Elian’s heart to the Sea Queen or remain a human forever.The ocean is the only place Prince Elian calls home, even though he is heir to the most powerful kingdom in the world. Hunting sirens is more than an unsavory hobby—it’s his calling. When he rescues a drowning woman in the ocean, she’s more than what she appears. She promises to help him find the key to destroying all of sirenkind for good—But can he trust her? And just how many deals will Elian have to barter to eliminate mankind’s greatest enemy? less

From the author of To Kill a Kingdom comes Princess of Souls, a Rapunzel-inspired YA fantasy romance about a teen witch groomed to steal souls for an immortal king and the reckless, rebellious boy to whom her fate is tied.For sixteen years, Selestra Somniatis has been trapped in a castle on the Floating Mountain, preparing to take her mother’s place as King Seryth’s right hand... moreFrom the author of To Kill a Kingdom comes Princess of Souls, a Rapunzel-inspired YA fantasy romance about a teen witch groomed to steal souls for an immortal king and the reckless, rebellious boy to whom her fate is tied.For sixteen years, Selestra Somniatis has been trapped in a castle on the Floating Mountain, preparing to take her mother’s place as King Seryth’s right hand. Tied by blood to steal souls for the immortal King of the Six Isles, the Somniatis Witch foretells the deaths of participants in the Festival of Predictions. To outrun your fate is to save your soul and steal the King’s immortality. But if you die, your soul is forfeit. And though thousands have tried, nobody has ever beaten death.As a soldier in King Seryth’s army, Nox Laederic is an unlikely candidate for the Festival, but he has no plans to die at the hands of the King or his witches. His plan is more akin to violent revenge: steal the King’s immortality and kill the entirety of his court, starting with Selestra herself.But when Selestra touches Nox in her very first prediction, she sees her own death alongside his--their fates are unmistakably intertwined, and Selestra is no longer safe in the only home she’s ever known. Nox and Selestra will have to enter a turbulent alliance in order to survive long enough to free the Six Isles from King Seryth’s clutches and escape the new fate that hunts them. less