Maiden of Midnight

Destiny Maladur is an Assassin.
Working loyally in her family business, she is the one tasked with eliminating... problems that they encounter, and this time, her work includes a fifteen-year-old boy from another world. Seth Smith.
Eager to prove her name to her family, and uphold her reputation as Caliem's Greatest, she will pull off her biggest deceit yet: Convince this boy they are in love, gain his trust, and then stab him in the back.
The only problem? They're Connected. Soulmates.
And if he dies, she dies with him.