In a fantasy world similar to ours, magic worked similarly to physics, with each elemental spirit magic being tied to a state of matter.

Earth is solid.
Water is liquid
Air is gas.
Fire is plasma. 

Four elements, four states of matter.

However in the ancient world of Hitarea, "Plasma" hadn't been discovered yet. The people of this world believe that only three states of matter existed, and thus, only three elemental magic could exist. For years, Earth, Water, and Air stood alone as the three main elements from which all others originated. Advanced arts like metal from earth, or Ice from water were only extensions of their original element . . . so what does that make Fire?

Fire is powerful as the earth with its mighty explosions, flexible like water as it writhes around in the air, and swift like the wind.

All at the same time.

Fire, in regards to combat, is the most powerful element by far. This fearsome power is Alden's to master, but this power is a double-edged sword. One shouldn't play around with fire if you don't want to be burned.

The fire within can be scary, you know?