Learning
There are three ways someone can learn Healing. The first is being taught by an Artisan+ ranked Healer if you already know a magic, or a Master+ ranked if you do not.
Another method is an intense emotional desire to fix someone, especially if you've exhausted all of your medical knowledge. This occurs most often in the medically inclined, doctors, herbalists, medics, etc.
The final method is the rarest. It occurs when you are mortally wounded, with no hope of rescue.
Lay on Hands
Lay on Hands is the first Healing function a Novice learns. This method expresses itself through the magic being pushed outward through the skin, typically the hands, and applied like a salve to the injured area. The magic soaks in and greatly boosts the body's natural healing. This cannot be resisted by the patient.
In addition to this healing boost, it also gives the Healer control of the injured area. This can be resisted by the patient, if they are conscious. Healers, when in control, can knit bone back together, reconnect muscle, seal blood vessels, and many other procedures through this method.
Laying on Hands is draining both for the Healer and their magic, but also exhausts the patient as well.
Cleansing
Once a Healer has reached Journeyman rank, they can use Cleansing. This method is applied similarly to Lay on Hands, but rather using a salve like magical form, this takes the form of light. The light can be used to create sterile environments and tools, clean wounds, and purge poisons, venom, toxins, and infections from the body.
Cleansing can also be used to temporarily disorient and confuse various undead creatures, though it does no permanent harm.
Passive Zone
At Artisan Rank, the Healer can combine the effects of Lay on Hands and Cleansing to create a Zone of Healing. This magic is exuded in the form of a magic "gas" and shaped as the Healer deems fit. This zone is then sterilized and all natural Healing within is boosted. In addition, this zone improves the rate of healing from Lay on Hands.
Mental Healing
Mental Healing is one of the most dangerous and tricky methods, which is why it is only able to be performed successfully by Masters. The Healer establishes a connection with the patient by performing Lay on Hands to the source of consciousness of the being (the head in most races). They let their magic soak in, and once in control, they are able to combine the two minds.
This requires intense focus, and if interrupted could be incredibly hazardous to both Healer and patient. The Healer moves through the patient's mind, seeing their thoughts, dreams, and memories. They must seek out dead areas and remove them, or damaged areas and repair them. These can often manifest as horrors, fears, bad memories. This is a very touch and go procedure, and can often yield no, or even worse results.
Dangers and Side Effects
As with all Magicks, Healing has varying, negative side effects and dangers. All magic is addictive, and can often lead mages to using far too much magic. Doing so can cause anything from overexertion, to passing out, to loss of magic temporarily or permanently, to death.
Lay on Hands is the most magically intensive form of Healing, and risks draining both the Healer and the patient. If either, or both, are drained, the Healing can still be formed, but at the risk of aging either, or both, of them. The more Healing needing done beyond the limits of those involved, the more aging that occurs. This is permanent, and cannot be reverted by any known means, magical or mundane.
Cleansing is the least magically intensive form of Healing, and carries very little risk to patient or Healer. If the Healer runs out of magic, they simply cannot Cleanse. Creating a Zone of Healing functions the same way.
Mental Healing is by far the most dangerous to both patient and Healer. It's not terribly magic intensive, however, the Healer runs the risk of becoming trapped within the patient's mind, or vice versa. Both minds are at risk of dying while combined. The Healer can contract the insanity that is affecting the patient, or worsen the condition in the patient. The risks are so high that they often outweigh the benefits and should only be attempted by the most confident and trained of Healers.
Progression Summary
Novice - Healers at this rank can only perform Lay on Hands. They can heal most broken bones, some open wounds, and bruising. This level of healing drains them very quickly and should only be used to supplement other medical procedures.
Journeyman - Healers gain the ability to Cleanse. Their Lay on Hands can be more often, for more extreme wounds. At this rank, they can handle arterial and muscle repair.
Artisan - Healers gain the ability to create Zones of Healing. Their Lay on Hands can now handle nerve damage, and heal internal bleeding and organs. They can also teach Healing to Artisan+ ranked mages of another discipline.
Master - Healers gain the ability to perform Mental Healing. They can reattach limbs that were kept in decent enough condition, heal most physical disorders, and are even able to repair congenital damage and cure many diseases. They can teach Healing to anyone.
Grand Master - Grand Masters can heal just about any disease, wound, or birth defect. Through several procedures, they can regrow a patient's missing limb, and have increased confidence in navigating a patient's mind. Though a Healer cannot restore a soul to a body that has died, if given enough time, it is possible for them to restore a dead body to a healthy condition. However, it must constantly be maintained as it is not alive, unless a soul were to enter it.