Theonite

A young-adult urban fantasy duology following Joan, a teenage girl on a contemporary, Earth-like world who has spent years hiding her ability to manipulate air, fire, and metal, and Daniel Thundyil, a transfer student who turns out to be a theonite -- one of a race of elementally powered beings from another dimension. Their meeting draws Joan into a far larger world than the one she has always known. Written by M. L. Wang and set in the same universe as her later standalone novel The Sword of Kaigen. The author put the series on indefinite hold after two books.