Cursed (The Reign Duology #2) by RI Aryn:
 
Fate’s arrow has struck. Now comes the reckoning.

With the unveiling of her mother’s secret, Nyra takes on the burden of a treacherous queen, where she stands before her kingdom with blood that could destroy worlds.

The breaching of the Fatum Treaty demands an inevitable war bound to ruin everything she holds dear–her land, her people, her empire.

But will war remain a lingering thought in her when the truth of a curse surfaces? One that links to the death of her brother and is just as deadly. To cure it means treading into a realm of enemies, but more dangerous than them is concealing the symbol that now marks her arm for eternity in an immortal promise.

Across an ocean, the vampires face a dilemma that threatens the collapse of Xaedor.

The vampire prince, amidst all this, battles a curse of his own. Kaeden Castillo will stop at nothing to vanquish his Curse, even if it is the feye who possess what he needs, and even if it shatters the fortified walls Xaedor has erected around itself as a shield from the world.

But is death truly what he should fear when Aelora Mairi stands beside him as his wife, as lethal to him as any curse?

Kaeden knows better than to get too close. That is, until dangerous intrigue overpowers any trace of self-restraint.

Xaedor and Elantris hold too much history and betrayal between the two to ever be amiable.

Fate, however, always knows how to nock her arrow–and this time she aims straight for their hearts.