Ozzy's ideas about dimensional are good. Also, I have no lore knowledge so what is here is based off what I have gleaned through observation of forum discussion.
Force: Sphere used to counter rushing tactics and enemy raides. Increases movement cost of enemies in your territory by one per connected force mana.
1 - Force Field: By utilizing electromagnetic forces, the caster can prevent units lower than his level from entering the tile on which he stands. Disabled if the caster moves. Useful for defending cities against hordes of fodder, or keeping resources from being pillaged. Increases in usefulness with time as caster levels. (yes, inspired by the FF archmage spell if you were wondering

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2 - Weight Manipulation: By manipulating the force of gravity acting on a person or object, the caster can add the light or heavy promotion to all units in the tile it is cast in. Utilizes two promotions I rarely if ever see used, and can allow role specialization of your units, or even enemies if the mage is invisible or something......
3 - Attractive Repulsion: By mastering the fundamental forces of physics, the caster can push units in surrounding tiles away one tile, or pull them onto his own tile. Units must be lower level/weaker than the caster. Useful for emptying cities of defenders, rescuing your own isolated units, getting something that's just out of reach, or getting by those blocking your path.
Creation - Assists in maintaining a healthy and productive society. +4% hammer output per city per mana resource connected.
1 - Craftsmanship: By harnessing the industrious spirit that powers a civilizations greatest accomplishments, a caster can give melee units in the same tile copper, iron, or mithril weapons based on already connected resources, exactly as a city does now. Saves having to go all the way back to a city to upgrade your armies equipment, if you cant afford or don't want to do so.
2 - Pioneering Spirit: By kindling the pioneering spirit which drives society to new heights and locales, a mage can found a new city by encouraging rapid immigration to the spot. Saves time building a settler, but if you spam cities everywhere you'll still need to find some way to pay for them.....
3 - Bountiful Harvest: By tapping into man's genius for keeping himself feed and reaping the greatest yields possible from the land, an archemage can negate the effects of starvation on a metropolis. Castes a spell which creates a building in the city providing whatever food deficit is being experienced by the city. Useful for when those fracking privateers plunder your fishing ships or the coming of blight as a stopgap measure against depopulation. Useless in cities which have a food income of 0 or greater.