If you want it to be inspired by Codex Alera and Avatar, I don't see much reason to go beyond the Air, Water, Earth, and Fire. Then, you could have each strange or non-standard aspect be a subset of the above. For example, since Fire produces a lot of radiation, it would make sense for a subset of furies to be other kinds of radiation (light, electricity, maybe magnetism (but maybe not).
Fire - Heat (basic), Cold, Light, Lightning (electricity). Creating heat means inducing Kinetic energy, so speeding people up or slowing them down. Smoke, Darkness.
Air - Wind, weather (esp. in conjunction with water), Sound (pressure waves). Senses - Smell, Sight, Hearing all depend on things moving through the air, though sight might better be handled by Light in Fire. Maybe light should be in Air, since light is both a particle (air-like) and a wave (heat-like), and fire seems to have a lot of stuff.
Earth - Manipulate natural minerals, like dirt, stone. Metal, Glass. Earthquakes. Sand. Wood, maybe, esp. in conjunction with Water.
Water - Manipulate water (basic), healing, Life-oriented stuff (e.g. bloodbending from Avatar, wood furies). Disease. Ice, Snow, etc. Weather (esp. with air).