Mask of Shadows by Linsey Miller

Sallot Leon is a thief, and a good one at that. But gender fluid Sal wants nothing more than to escape the drudgery of life as a highway robber and get closer to the upper-class and the nobles who destroyed their home.

When Sal Leon steals a poster announcing open auditions for the Left Hand, a powerful collection of the Queen’s personal assassins named for the rings she wears — Ruby, Emerald, Amethyst, and Opal — their world changes. They know it’s a chance for a new life.

Except the audition is a fight to the death filled with clever circus acrobats, lethal apothecaries, and vicious ex-soldiers. A childhood as a common criminal hardly prepared Sal for the trials. But Sal must survive to put their real reason for auditioning into play: revenge.