World Laws Part 2

"Yes. The world has many elements, but they only consist of a single element each. There can be no two elements merged into one. While it is possible, as you know, it breaks the laws of the world. No one should have the mana to even sustain such a spell, but you are different. You have a vast amount of mana within your body that even surpasses myself. 

"Because of this, you are able to create a fusion between elements and even use it as a spell. But…. if that spell grew out of your control it would create zones that no one would be able to tread. And those zones would grow bigger due to the elements in the air. The affected zone would suck in the two elements it is made of and slowly expand while using the mana in the air to feed the spell without relying on the caster. It would be a kind of elemental being that goes against the laws of nature. This is why elementals are only made of one element." The spirit leader explained.