Fireshrine

Davina is the first princess of the royal family Vermillion of the Crimson Empire. She feels like a failure, being the only royal in her family unable to control the fire element.
Sylver is the first prince of the royal family Asturias of the Cyan Kingdom. Unlike Davina, he has complete control over his element. The two are sworn enemies, whose kingdoms have been at war for centuries. Either would do anything to stop the war.
Noella is a genius. Without the possibility of gaining the throne, she throws herself into helping her brother end the bloody war between the two kingdoms. But she has a secret, something not ever her brother, the future king knows.