The Rise Of The Elements

Yunari Terre was thought to be useless...talent-less...and most of all, harmless. She lives a peaceful life with her adopted younger sister, Mizuki Aquavine who could control water and her older sister Etherine, the pride of the Terre family, masters of the earth element. Yunari however, can't control anything. Or so she thought...
When the fire king commands attack upon families of other elements, the Terre family gives Yunari a test. Yunari turns out to be the chosen one, destined to overthrow the fire lord and rule the lands. This only happened once in ten-thousand years and every time, war broke out.
The Terre family is afraid of Yuari and tries to kill her. With the help of Etherine, Yunari escapes together with Mizuki.
Along her journey, Yunari finds reason to kill the fire lord and with the help of comrades along the way, she seeks revenge upon the fire lord, but what will happen?
Will Yunari fail her quest? Or will she claim the throne?