King’s Imitation by Erin Grunke

Survival is not an option – it’s a demand.
Andrea is a sword-wielding royal, but when she finds out she’s not the real heir to the throne, she convinces her parents to let her fetch the true heir.
However, being a king was never what Gavin wanted.
As Andrea brings a whirlwind of change to Gavin’s life, he comes to realize that maybe he does want to take the throne. But killers hound their every step, and the palace is not the safety it once was.
Through the tension, fights for their lives, lies, and betrayals, they need to discover the legends they’re up against or their lives may end before they get a chance to find out the truth about themselves…