The other complication involved is that by the technicalities of the universes fundamental workings, you are for all intents and purposes, undead. You are still wholly alive and functioning of course, magic affects you as if you were alive, you heal at the normal rate, you still need the basic metabolic requirements of all living animals (assuming the Necromancers didn't remove them from you), but magic will also treat you as if you were undead, and the words of priests and paladins will repel you and burn you. Its something of a grey area.
There are four colleges of the Surgeon-Necromancers, each with their own specialties and services; Xanthic, Mavric, Elaic, and Vyssinic.
The Xanthic College is the colour of old bile, and acne. Grand brass vats seethe and boil on the fringes while other pots, pans, furnaces, and presses are put to furious work all about. The knives of the Xanthic Surgeons are red-hot during the processes, the better to cauterise the wounds they must inevitably inflict. The ministrations of the Xanthic Surgeons are, clearly, the most painful.
The abilities they can grant you are mastery over fire, pheromones to instill vigour and strength into those around you, and the mental strength to dominate minds. Fiery strength, liquid rage, and dominance pheromones are produced in the cinder-glands of the Xanthic college. They can transpose all such attributes that belong to creatures possessed of excess rage and vitriolic temperament. They do tend to increase the irritability of the wielder, but that is surely a small price to pay for such powers.
The Mavric College is a deep black, like the night sky unspoiled by the pathetic sparks of stars. Deep pools of oils and unguents are brewed in vast halls that reek of fat and dirt. Smoke and fumes play large roles in the Mavric Surgeon's works, and their suction masks for the protection of the surgeon and the patient have yet to actually kill anyone. The tall tales of ragged, lipless faces are surely just the poor ravings of dissatisfied customers.
Mavric Surgeons bestow abilities that protect, that give authority over flesh and over the earth itself. Their grit-sacs can project darkness, fear, and hallucinations. Creatures that lurk in the dark and seldom brave the light are fair game to the Mavric Surgeon; though such melancholy can cling to the organ's new bearer. The Black Elixir will hold the worst effects at bay of course...
The emerald cathedral-theatre is the Eliac College. Vast pipes of viscous teal and jade tar flow all about the space, only leaking sizzling drips into the corners that no-one cares about. Syringes and Injectors are the preferred tools of the Eliac Surgeons, and very few ever complain about air being injected into them...
Powers over fluids, of healing, and fetching or summoning are the specialties of the Eliac College. The glassy fibres they bestow can calm and equalize, or inflict inequalities in the humours of those they touch. Sometimes they can even be impelled to act as secondary limbs, though only the very highest quality surgeons can accomplish such a feat.
And finally, the blood-red Vyssinic College. Pay no attention to the wasp-hives that dapple the walls in grist-comb, it would only raise more questions than we have time for answers. Satisfy yourself with the knowledge that the honey they produce ensures the Vyssinic Surgeon's success in their procedures. Neither should you give any mind to the grand bellows they cart around to each Surgeon's practicing area. They merely require them to achieve the proper 'atmosphere'.
Either way, the Vyssinic College is proud to bequeath to their customers the powers of unshakable resolve, command of lightning, and irresistible charm. Flight is beyond most Surgeon-Necromancers, but the most skilled of the Vyssinic College are whispered to have mastered the arts necessary to confer the freedom of the skies to their patients.
The process of becoming a patient of a College involves a staggering amount of patience and paper-work, staggering amounts of money, and finally, staggering amounts of pain. Then and only then will they accept you as a patient to go under the knives and implements of the Surgeon-Necromancers. They first must ensure that your humours and levels are within their acceptable ranges, and that you are fit and healthy (roughly speaking) before they strip you, clean you, bathe you in a kind of thick, syrupy goo, and then finally sedate you. Unfortunately, their sedation methods aren't quite as refined as some would like, and there are a few horror stories here and there of patients awakening to find the many limbs of a Surgeon rummaging about inside their flesh.
The methods and techniques of their work are closely guarded as to be worth the weight of the College buildings in gold, and the formula of the dark elixir is unquestionably priceless. So far, the Surgeon-Necromancers remain unique in all the worlds, though not for the lack of trying from their would-be competitors; though they often end up being hung and burnt by lynch mobs for their unspeakable acts in the name of imitation.