The Division

Geological / environmental event

The hostility of humans to their kind was becoming more violent and dangerous and so working together the most powerful witches of the time and earth and water fairies they sort of just broke off a large chunk of the continent and pushed off further into the ocean so that humans would have a harder time coming to attack them. It took years and caused multiple deaths, it caused lots of damage as well with destroyed buildings with unintended landslides. It's believed the excess magic use soaked into the islands, which is why the flora started exhibiting more wild magical properties after isolating from humanity. With the flora becoming more magical, and most of the fuana either eating magical flora, or fuana filled with magical flora, it caused them to mutate as well. This in turn is thought to have helped strengthened the magical traits in the population of Mayvis and why humans eventually just died out as no one was born human again.