The Amagarians Series by Stacy Reid

The darkest taste of temptation… Fleeing from a blood oath made against her will to the tyrant king, the last place Princess Saieke expected to be trapped was in the Darkage—the land of the feared shadowed demons. Even worse, she's stuck with Archduke Drac EL Kyn—a creature of darkness and sensuality, who entices her with reckless passion. The only thing she needs from the fierce warrior is his body to further her plot, certainly not the soul-searing desire he rouses... moreThe darkest taste of temptation… Fleeing from a blood oath made against her will to the tyrant king, the last place Princess Saieke expected to be trapped was in the Darkage—the land of the feared shadowed demons. Even worse, she's stuck with Archduke Drac EL Kyn—a creature of darkness and sensuality, who entices her with reckless passion. The only thing she needs from the fierce warrior is his body to further her plot, certainly not the soul-searing desire he rouses. Shadow assassin Drac must unearth the factions who murdered the dark king. Drawn by an irresistible hunger to the princess, he struggles to maintain distance from a woman who is forbidden to those of his race. As she navigates the traps laid for her by enemies, Drac must decide if he will claim Saieke as his mate or relinquish her to avoid embroiling his kingdom in war... less

Heavy is the crown of darkness…Lachlan Ravenswood lives in cold, emotionless exile lest he tempts the demon within him to rise. For centuries he’s denied its darkest urgings, his duty to the realm as a shadow assassin the only call to which he responds. Until her. Shilah Symonrah, an Imperial telepath on a mission to liberate her own kingdom from a tyrant, arouses every protective and lustful instinct within him... moreHeavy is the crown of darkness…Lachlan Ravenswood lives in cold, emotionless exile lest he tempts the demon within him to rise. For centuries he’s denied its darkest urgings, his duty to the realm as a shadow assassin the only call to which he responds. Until her. Shilah Symonrah, an Imperial telepath on a mission to liberate her own kingdom from a tyrant, arouses every protective and lustful instinct within him. But in a desperate bid to escape their mutual enemy, the Empire of Mevia, Shilah accidentally releases the demon inside Lachlan—awakening a deadly threat that could consume them both. For a terrifying prophecy foretold Shilah reigning as queen of darkness, a vision she did not understand until now. And if she succumbs to the searing passion between them, she will unleash forces that could destroy their very world… less

She had no idea what one night of forbidden pleasure would unleash... The violent and all-consuming power of the Phoenyx is awakening inside Princess Xian, and she's a powerful temptation for kingdoms greedy to harness her might for themselves. Now that wars been declared Xian must cement more power for her kingdom, by marrying a man her king decreed... moreShe had no idea what one night of forbidden pleasure would unleash... The violent and all-consuming power of the Phoenyx is awakening inside Princess Xian, and she's a powerful temptation for kingdoms greedy to harness her might for themselves. Now that wars been declared Xian must cement more power for her kingdom, by marrying a man her king decreed. The enigmatic Gavyn Westk'arr rouses an inexplicable hunger in Xian's heart, and she's determined to take a night of passion with him before surrendering to her duty. Little did she know that one taste of her chakra would unleash a beast within him and an unexpected passion that will force them to make sacrifices that will shatter their hearts. less