OC Story Worldbuilding

There are two types of magic in this world. Innate and Learned, this will mostly cover Innate magic as learned magic is picked up from spellbooks, and can be picked up by anybody, regardless of if they have innate magic or not. 

Innate magic is, as implied, innate. Though research into it has not been as extensive as it could be, due to conflict between the magical scholars and the scientific community, it is believed that possessing innate magic is genetic. Innate magic itself is divided into elemental categories that usually manifest in adolescence and solidify as one matures into adulthood.

Light 
One of the most powerful forms of magic, believed to be the pure energy of the Guardian Spirit. Purifying, healing, and able to manipulate visible light to the user's will, this power is a force to be reckoned with when used properly. It is able to be used anywhere there is even the smallest slivers of light.

Due to it's power and holy associations, the Church of the Chromatic Order of the Guardian Spirit restricts it's use to clergy members, who are extensively trained on it's proper usage. 

Shadow
One of the most powerful forms of magic, believed to be the vile energy of the Traitor Spirit. Corrupting and able to manipulated casted shadows, this power is often known for it's sheer ability to be destructive. It can be used anywhere even the slightest shadow is cast. 

Due to it's destructive ability and demonic associations, the Church of the Chromatic Order of the Guardian Spirit bans it's use. Shadow magic users are encouraged to "get rid of" their magical ability, typically through the blessing of a light magic user, sealing their abilities away. Persons found to still practice dark magic knowingly are subject to whatever punishments the Chromatic Order sees fit.  

Fire
Derived from light magic, 

Ice
Derived from shadow magic,

Growth 
Derived from light magic,

Decay
Derived from shadow magic,  

Wind
Derived from light magic,

Earth
Derived from shadow magic, 

Typically, once a child first starts showing signs of innate magic, it will maintain the same elemental properties forever. However, a handful of incredibly rare cases of element switching have been reported. The cause is unknown, but some believe it to be caused when an adolescent (typically 4-8 years of age, cutoff for change at 10 years) experiences a major traumatic upheaval in their life and subconsciously adapts an element that is better suited to their circumstances. It is also believed to only be able to change from light and shadow magic into one of the six other types, typically an opposite derivative (i.e. a former light magic user switching to ice).