Replying...
Intro. Korra is traveling alone through the Earth Kingdom after the main events of the series. During his journey, he feels a disturbance in the spiritual balance. When approaching a river, he sees someone practicing waterbending, but he also detects that that person can use earthbending and firebending at the same time. That baffles her. Only the Avatar should be able to master all four elements.

Procedure

@Shion