The Blood Trials : Book 1 by N.E. Davenport

It's all about blood. Blood spilled long ago between the Republic of Mareen and the armies of the Blood Emperor, ending all blood magic. Now there is peace in the Republic - but there is also a strict class system, misogyny, and racism. Her world is not perfect, but Ikenna survived in it. Until now.

With the murder of her grandfather, Ikenna spirals out of control. Though she is an initiate for the Republic's deadly elite military force, Ikenna has a secret only her grandfather knew: she possesses the blood magic of the Republic's enemies. Ikenna throws herself into the gladiatorial war games at the heart of her martial world: trials that will lead her closer to his killers.

Under the spotlight, she subjects herself to abuse from a society that does not value her, that cherishes lineage over talent - all while hiding gifts that, if revealed, would lead to execution or worse. Ikenna is willing to risk it all to find out who killed her grandfather... So she can end them.