Elemental

A person born with the ability to control one of the four elements.

Elementals can all control one of the four elements each; Paper, Smoke, Metal, or Cement.

People who are elementals are almost always born to elemental parents, though occasionally a non-elemental couple will give birth to an elemental.
At some point between the invention of easy fusion energy and the NEOWar, people started popping up who had the ability to control one of the four elements more and more. Supposedly, people with such powers have been present throughout all of history, but for whatever reason around that time the population of them exploded, and nowadays elementals are commonplace.