Godsgrave by Jay Kristoff

Assassin Mia Corvere has found her place among the Blades of Our Lady of Blessed Murder, but many in the Red Church ministry think she’s far from earned it. Plying her bloody trade in a backwater of the Republic, she’s no closer to ending Consul Scaeva and Cardinal Duomo, or avenging her familia. And after a deadly confrontation with an old enemy, Mia begins to suspect the motives of the Red Church itself.

When it’s announced that Scaeva and Duomo will be making a rare public appearance at the conclusion of the grand games in Godsgrave, Mia defies the Church and sells herself to a gladiatorial collegium for a chance to finally end them. Upon the sands of the arena, Mia finds new allies, bitter rivals, and more questions about her strange affinity for the shadows. But as conspiracies unfold within the collegium walls, and the body count rises, Mia will be forced to choose between loyalty and revenge, and uncover a secret that could change the very face of her world.