Guardians of Alistle Risen from Ash by Samantha Vargas:
 
“What do you want, Little Flame?”

It was a question Kienna never dared to ask.

Raised behind the impenetrable Orb of River Storm, Kienna is destined to serve and protect her city as the Starborn from the evil festering beyond the barrier after the War of Liberation. She, and four other Guardians, are gifted magic by the great and powerful King Vaerin.

Then Kienna discovers the king’s secret and throws his gift back in his face.

When River Storm’s lies shatter, Kienna makes the impossible choice to help a rebel army tear down the Orb and run. She never expected the other Guardians to follow. Now, hunted and broken, they discover a world far different than the one they were taught to fear. A world that forces them to question everything, including themselves.

As loyalties fracture, and kingdoms prepare for war, Kienna must decide who she truly the obedient weapon the king forged…or the flame that will burn his empire to ash.

One Flame to defy fate, if she has the strength to let it burn.