Think of a 'bad wizard.' They're a necromancer, right? Maybe a rat mage, a pyromancer, or a witch.
Now think of a 'good wizard.' Light mage? Healer? Lovable illusionist?
All of those are wrong.
Shadowmancers
Shadow mages get a bad rep. Sure, in the civilized lands they conjure darkness, despair, all the crap, but Shadow mages are, by and large, pacifists.
Shadow is scary, but it in itself can't hurt you. Shadows can blind, but when the darkness clears, you'll still be able to see. But if light blinds? You may never see again.
Shadow mages in most lands are thieves and tricksters, using their magic to enhance their larcenous skills. It is an art rarely taught outside criminal circles.
In the Inkal desert, Shadowmancy is one of the most taught schools of magic. It is powerful, versatile, and useful. During the day, it can be used to hide from the burning heat of the sun. At night, it grants concealment in an otherwise flat land.
The north is the one place where Shadow mages are almost exclusively evil. There, powerful shadow mages shroud entire valleys in darkness, blotting out the sun and bringing a cold, dark, slow death to all inhabitants, after which they descend to claim the spoils of war.
Pyromancers
Fire is dangerous. In the middle-lands, pyromancy is feared, much as anyone would fear someone carrying a Molotov cocktail everywhere they went. It is dangerous, volatile, and causes too much collateral damage to be safe.
However, in Inkal, pyromancers are praised for their ability to turn sand to glass quicker than any forge. Great works of art, palaces, and even, once, and entire city have been raised by a dedicated pyromancer.
But, it is in the northern lands where pyromancers are granted the most respect. The north is cold, and fire is warm. Pyromancers bring light and heat to entire tribes during the long months of dark and snow. Many tribes have survived solely because of the loyalty of a single fire mage.
Enchanment
Of all the schools of magic, enchantment is the only one universally feared, and regarded as evil. Taking away the free will of a person or creature, while powerful, is regarded by most as the height of immorality. Enchanters survive through secrecy or fear, and entire armies have been raised to kill a single mage who went too far into the depths of mind-magic.