Magic
Nyonia is a world filled with magic and wonder. The Elder Races believe that Gods, specifically Siem - Never-Changing Lord of the Azure Bowl, made it possible for the inhabitants of Nyonia to use magic. The Glauberg mage, Ambernaud, discovered there is an energy which is created when the reality where Nyonia exists 'rubs' against another reality, where Nyonia does not exist. Ambernaud's student Malagaw later discovered that Siem gifted each of the inhabitants a specific ability to channel this energy.
In a few rare cases there have been individuals who had an affinity for multiple types of magic. Some of these individuals tried to learn each of the different types of magic. Every mage who has walked that path has not only destroyed themselves but caused a world wide cataclysmic event.
Multiple mages who practice different types of magic can combine their efforts without the risk of causing a cataclysmic event.