A Siren's Heart's Desire by Melinda Clark

As a reborn mermaid, Amandine is tasked by her Goddess to go ashore during the equinox and obtain a chosen human’s heart before the following Blood Moon. In exchange, any wish of her choosing will be bestowed upon her. Though the chosen human, Marc, is unaffected by Amandine’s mystical charm, she waits patiently for the prime moment to carve out his heart and deliver it to her creator. As she learns more about him, Amandine finds that the reason Marc can resist her allure is in his blood; making him even more special than she had once perceived him to be. The longer she is among the humans, the more Amandine’s mind recalls about her previous life as one of them. Her emotions, in turn, also seek to deceive her; allowing he and his daughters to slowly become a part of her once-numb being. Seeing the possibility of unfaithfulness, one of her kin decides to take advantage of Amandine’s weakness and pursue the task of killing the human herself; therefore, being entitled to get her own wish granted. Amandine must choose: Complete her mission and obtain her blessed wish, or protect the family and be disloyal to the deity who gave her this existence. Will she cast aside her own feelings in the name of her duty? Or will she realize, in the end, what her heart’s true desire is?

Demon Tamer (Divine and Hellish Series) by Melinda Clark

Growing up as a human witch in a land where magick is common, a lot was expected of Andromeda when it came to honing her magickal skills and talents. Sadly, she’s come up short in that department. Clumsy and unable to focus, her spells usually flub. Most days it doesn’t bother her so much, except now as a warlock is sweeping through the land and devastating nations before adding them to his empire. His armies have already crossed the border and wiped out her town, taking her mother and grandmother with them. In an act of desperation, she seeks to perform one of the nation’s taboos: to summon a demon, a witch’s greatest enemy, in order to use its power.Summoned from the Hell Realm by the little witch, Rowan is a half-demon with something to prove. Humans and demons alike have always treated him as lesser. Everyone he encounters either wants to kill him or use him for their own needs before tossing him away like trash. He expects Andy will treat him no differently, but finds that she is not exactly what he imagined she would be. But a deal’s a deal, and when he is done with the warlock, he will have himself a taste of the little witch. Her soul, no matter how weak, will increase his own power exponentially and allow him to fulfill his desire of ascending the demonic ranks to that greater than his father. He will finally have what he wants from them all: their fear and respect.Two enemies must work together to achieve their goals. Will Andy be able to show him that not all humans are created equal? Or will Rowan find a way to consume her soul before his end of the deal is done?