Game idea - 4 semi-original healer classes

I think a good rule of class-based character design is to make sure that a class's benefits always come with disadvantages. That is to say, any one class shouldn't provide a better advantage relative to other classes, because that might knock the game out of balance.

This usually comes up in terms of combat-based classes and their abilities to deal damage. But I'm thinking about healer classes today. For example, your fantasy-standard white mage has powerful curative spells but is awful at direct combat; or there's the AD&D cleric who (if aligned with the benevolent gods) can heal wounds but can't fall out of favor with their deity. Healers are not a flashy choice for a player due to their low damage output; rather, they're good classes for players who are interested in assisting other players.

One more note before this list: just like certain authors deliberately set rules for their writing (e.g. "I'm not going to go over 10 pages with this story,") it can be fun for GMs and players to think about restrictions (or disadvantages) as role-playing opportunities.

So here's a simple list of healer classes and their benefits and disadvantages:

Faith healer Consider the televangelist: a big, loud personality who never misses an opportunity to thank a certain powerful being. A faith healer could be considered a healer-broker: he or she will present opportunities to spirits who in turn will demand payment. Sometimes the payment is steep. Faith healers typically seek easy marks among deities, running the risk of appealing to opposing deities or failing to pay the deities back for favors. Occasionally, faith healers are themselves the targets of spiritual scams. A faith healer might be a former salesperson, and he or she can often be found looking sidelong to benefit from some situation.
Advantages: If they convince their deities or spirits to act, faith healers can invoke powerful curative forces that can heal a wide variety of ailments.
Disadvantages: Faith healers need to persuade their "congregation" (e.g. the other PCs and NPCs) to help convince the spirits to act. If they fail to do so, the deities might not act or might act out of malice. They might also extract high prices from the healer's party.

Leech Think of a medieval physician mixed with a junkyard tinkerer. This person believes in physiological theories that differ from mainstream knowledge of the body, and they deploy commensurate "cures" that sometimes do more harm than good. A leech would think "why fix a broken arm if you can find another?" Leeches are also usually neutral in alignment, forgoing moral action--like the desire to alleviate pain--in order to further their knowledge. A leech might not wait for one's death to begin dissection if death would impede learning.
Advantages: The leech is a master of tissue replacement, transplantation, and reanimation. If the materials are available, there are few bodily ailments for which a leech can't hack a workable fix.
Disadvantages: A leech's medical practices might seem uncharismatic or downright offensive to some.  Leeches arouse disgust and avoidance in most people, and a party of PCs that includes a leech must be ready to suffer penalties to dialogue encounters. The effects of a leech's practices might be permanent and life-changing, such as the functioning of new body parts, the gain or loss of abilities, and physiological needs that don't reveal themselves until later.

Infirmant Infirmants are evil doctors guided by the principal of curing ailments with more powerful ailments. Their treatments are ostensibly curative but always corrupt. An infirmant might treat a grievous wound by implanting a cursed totem to seal the wound with radiant putrescence. He or she might introduce a demonic parasite to eat a tumor, or seek out a particular beast's vitriolic blood for a patient to drink. The only catch to the infirmant's supernatural treatments is that the patient must consent. Infirmants are also occasionally tasked to do a deity's bidding, which is never pleasant.
Advantages: Infirmants are great for quick heals when time, equipment, and concern for the future are scarce.
Disadvantages: Infirmants can't treat PCs that don't consent. Beyond that, the long-term propositions for an infirmant's skills are rarely comforting. Dangers include bodily possession, maddening pain, and the generally intrusive malfeasance of evil forces. Whatever the case, an infirmant's healing powers are never benign. However, if the PC party actually wants to consort with supernatural evil, an infirmant's practices might benefit them over time.

Anatomancer Anatomancers are psychopathologists who can travel through the psychic plane. In an act of intense concentration, the anatomancer's psychic presence enters another close body to fight off a disease or purge a foreign presence. He or she can also influence bodily tissues' physiological processes, like cell regeneration. Although some mercenary anatomancers exist, anatomancers are more employable for benevolent purposes than murderous ones due to the time and patient's cooperation required to treat a patient. Veteran anatomancers can bring other PC's psychic presences with them into a body. (A GM could anthropomorphize a disease to create a combat encounter in a PC's body.)
Advantages: Anatomancers need no specific equipment. Because of this and their occupational interest in the minds of others, anatomancers often learn a wide variety of skills and make good multiclass PCs.
Disadvantages: Since they are unable to create new matter, Anatomancers can only work with existing tissue. Anatomancers also become vulnerable during their healing trances since they lose contact with their bodies.