ENGINEERS

The 1st Estate.  Wizard schools are like monkly orders, in that energy is donated to them by wealthy patrons or governments, and they are able to use this debt energy and do whatever they require with it, owing nothing should the wielder die.  It is borrowed in some fashion.  They're like traders on wall street, spending other people's money.  More powerful wizards have to be able to demonstrate publicly that they are capable and trustworthy enough to be given ownership of enormous quantities of precious spirit energy.  As a result more powerful wizards are typically much older, like hedge fund managers.

Bonded Engineers (wizards/mages) are like public utility workers.  They make the water flow, the plumbing and waste management work, they oversee animal husbandry, agriculture, horticulture, they make the power flow.  They arrange architecture on the fly, shoring up structures and rearranging buildings to maximize available space.  They serve as doctors and undertakers (a particularly important job with so many dead bodies).  They function as police surveillance and accompany them on tough calls to utilize battle magic.  They put out and start fires.  They control the weather and climate.  They create walls of force and push out poisonous ether fumes and keep them out.

In war they turn their skills towards combat, and primarily duel eachother for control of the battlefield.  Should one win, he will have unnoposed Elan over the area of control and wreak unobstructed havoc, like a bomber carpeting the area with explosions.  In which case enemy armies make a beeline for him.  He needs safety and line of sight to work, otherwise his attacks are indirect bombards, and it's hard to work with a bunch of bolts flying at him.  Engineers in combat function like small artillery and air support for this reason.  Because use of their elan causes damage to their bodies, they tend not to live long, but do not go to hell when they die.  Like everyone else, their supply of elan is limited by what they've been assigned.  If they use it up in combat, they cannot get more unless a banker is around and replenishes it.  They are not warriors, and if they can't defend themselves with their magic, they don't live long.

For this reason, being an engineer is a high risk/high reward profession.  It has huge benefits, like high pay, great living conditions, a stipend living allowance, basically making one middle class.  It also ensures you don't go to hell, and your extra pay helps get loved ones lighter punishment.  In theory.  Many times they STILL get screwed, wasting all their pay on helping loved ones while they're making an income, and leaving nothing for themselves, forcing them to go into debt.  They die younger than average of course.  If they get into legal trouble they're protected and represented by the engineering school they belong to.

Very successful engineers get out of the trap.  They live longer, sometimes very long.  They are too important to let waste away, so expenses are devoted to keeping them alive and working elan.  They command HUGE amounts of Elan to make things work.  They are like demi-gods, seldom seen but worshipped.  They are still mangled and twisted physically by their elan, but survive and thrive as avatars of their school.

Architectual masters are turned to greek statues.  Horticulturalists become underground fungi fields.  Kludge Masters become metal trash monsters, fusions of machine and flesh, hydro engineers become huge whales.  THe doctors, master surgeons, master undertakers, etc, become dessicated liches, and so on.  They are revered as gods.