In the beginning, the world of Archai was a single, massive continent that was home to all of the elements. The Elemental Gods and their followers were able to co-exist in one centralized location because of a pure need for each other. No one element could survive in Archai without the use of others in some fashion. Those four elements are Fire, Air, Earth, and Water.
Prophets had long feared that a day would come where someone would try to combine the primary powers of one element with the secondary powers of another. They predicted such a creation would trigger a cataclysmic event that would be responsible for the destruction of the world of Archai.
Time would unfortunately prove their theory to be correct...