War Wizard Categories: War Wizards are thematically and mechanically oriented around combat magic, but the mechanics side and the lore side are different. In the setting history, War Wizards tend to focus on the four elements of Fire, Water, Air, and Earth. In practice, the damage categories are Fire, Ice, Lightning, and Poison respectively. There are multiple instances of this dichotomy being rationalized, justified, discussed, and even ridiculed in-setting.
Occultist Categories: Occultist are thematically described as magic researchers and theoreticians, in contrast to the practical and pragmatic combat magic of War Wizards. In practice they do have some damage dealing spells, but the damage is considered incidental or even accidental compared to the primary focus of their magic. Occultists tend to specialize in either Gravity, Time, or Mesmerism / mind manipulation.
Occultech Categories: The basic premise of Occultech is a unified theory of magic that describes all spell effects as energy in different media. Ironically while the process has streamlined magic in the setting, it does not actually match how damage and elemental vulnerability / resistance is calculated mechanically, so many Occultech devices and skills are categorized (sometimes arbitrarily) into different groups behind the scenes.
Earth Wizard: Earth themed War Wizards cover both the unliving stone and sand that makes up the earth, the living soil and plants that grow in it, and the decay of mortal remains that are buried beneath it. This explains their connection to necromancy and their Poison-based combat magic, and also gives them limited healing abilities. They are primarily associated with the Heart of Earth Temple, a religion that holds life, death, and undeath as equally vital parts of the natural world.
Fire Wizard: Fire themed War Wizards are straightforward in comparison to other types of wizard; they set things on fire. They also, less spectacularly, protect against fire, and use the symbolic and metaphorical properties of a burning flame to transform and change things on and off the battlefield. They are primarily associated with the Order of the Sacred Flame, a religious order of smiths and craftspeople.
Air Wizard: Air themed War Wizards utilize Lightning damage in combat, through the thematic association with the sky and stormy weather. ironically, spells directly manipulating the wind are uncommon, as the air-themed magical organization - the Confraternity of Eternity - emphasizes internal focus and transformation via breathing exercises. This means that Air Wizards gain various powers over their own bodies that can culminate in shapeshifting or physical improvements like increased strength or speed.
Water Wizard: Water themed War Wizards weaponize Ice magic in battle, and are otherwise affiliated with the transformative practice of Alchemy, which relies a great deal on physical water as a medium for astrological influence. Accordingly they are found in great abundance in the Alchemical Society alongside practicing Alchemists; in the parlance of the society, Water Wizards pursue internal transmutation - the body is mostly water after all - rather than external transformation through laboratory work. (A few purists insist that Water elemental magic is not true alchemy because a Water Wizard cannot undergo the Alchemical Great Work, but only a handful of Alchemists ever pull that off anyway.) The upside of being able to balance alchemical energy in a living body is that Water Wizards can provide even faster magical healing than Earth Wizards, and while their selection of buffs and enhancements are less flexible than what an Air Wizard can do, Water Wizards can apply those changes to other people. This has lead to Water Wizards accumulating a reputation as the "jack of all trades" of magicians and spellcasters.
Gravity Occultist: The most notable and desired ability of the Gravity Occultist, and the main attraction for aspiring magicians, can be summed up in one word, and that word is flying. Other abilities include increasing the mass of something or someone, which can slow down a pursuer without using time magic, or cause a ship to sink in the sea or a vehicle to get stuck in mud, and of course the same effects can be reversed to make a voyage faster (but not always safer) while truly refined skill can manipulate fine objects at a distance. Occultists who specialized in Gravity magic currently gather under the banner of the Rationalists, whereas previously they had no overarching faction affiliation and were thematically connected to the Heart of Earth Temple regardless of their actual religion.
Time Occultist: Time magic is poorly understood by outsiders, who think it can be used to predict or even travel to the future, as well as go back in time to change history. While time travel is not yet feasible (despite a small close knit community of historians and theorists working on it) and predicting the future is a crap shoot because of that whole "free will" thing, manipulation of time energy in discrete systems has become well established practice. Time Occultists can slow down their foes much like Gravity Occultists can, but they can also speed themselves and their allies up, which Gravity magic can't do. (Then again time magic doesn't let people fly, so it all balances out.) High level Slowdown effects can approximate stopping something in time, and subjectively anyone caught in a Slowdown effect experiences the world around them moving impossibly fast. Less flashy but arguably more important, anything that isn't alive (because of how living processes work) can be "rewound" back in time to an earlier state, making it possible to recover and restore previously lost works of art and culture and history. Time Occultists, like Gravity Occultists, have staked their claim under the Rationalist Movement, where previously they could be found in any organization with a vested interest in preserving and restoring lost history.
Mesmerism Occultist: The magic of the mind and the senses is often maligned, far more than necromancy ever was, for its potential for exploitation and abuse. Memories twist, illusions proliferate, and even questions of identity become difficult to answer. (More than one Mesmerist has tried to start a literal cult of personality in the Archipelago.) Strangely enough, the College of Bards has relied on specifically those attributes to revitalize and reform the image of Mesmerism, by offering illusion as entertainment on a large scale. Recent developments in Occultech, connecting Sound wave patterns in music and speech to Electrical activity in the thinking brain, now offer the potential for mass produced entertainment of astounding vividness and clarity, with no risk of mind control without a mesmerist on the other end. (There are some conspiracy theories that Occultech could allow mass mind control, and they have a basis in fact in the form of Silas Van Der Horne's research, but most of the people trying to produce mass entertainment have no idea about that - and neither do the fearmongers, funnily enough.) Mesmeric spells can stun an enemy, trick them into harming allies, disrupt morale and esprit de corps, scramble communications, and redirect aggression towards harmless decoys. Strangely enough, the leadership themed skills of the Hero don't register as Mesmeric magic when quantified by either traditional magical scrying or newer Occultech scans... despite the fact that there is clearly something going on there.