Charisma is the most supernatural implementation of the Reaction Modifier meta-advantage, so it is the most appropriate base for the supernatural forms. Tailored charisma is the permanent forms of the Ambiance effect, supernatural auras that modify reaction rolls (and occasionally other rolls) toward the charismatic character. A universal bonus to reactions is worth 5 points per level, a universal penalty is worth -5 points/level, but charismatic auras are much more varied, and often produce a mixture of both positive and negative effects depending on the situation. These can be built with limitations and enhancements, or simply estimated by the GM. Some examples:
The ability to work Ritual Magic at peak effectiveness. Mystic initiation can be a formal ceremony in which other initiates present the candidate to God and invest him with symbols of sacred authority, something learned through difficult training, a result of a vision quest to meet your spirit animal, something you acquire after a severe illness, or simply something you are born with.
I think the default should be Ritual Magic does not work for anybody without this advantage, but in some settings (including the Shadow War) anybody may attempt a ritual, at -5 to skill and with a maximum modified success roll of 12.
In many cultures this disease is regarded as a type of spiritual possession. If this is true in some or all cases it may be curable with appropriate spiritual protections, in which case it must be bought off. It also becomes a suitable disadvantage for mediums and other spirit magicians, a sort of Involuntary Possession that doesn't allow either the magician or the spirit to do anything useful. If the possession actually allows the victim any spiritual powers, purchase them separately.
Madness is a common theme in many tales, and attributed to a wide range of causes. The interaction of a particular type of insanity with both magic and technological medicine depends on its true cause. Hostile spirit possession can be cured by Exorcism, and is potentially treatable with other types of spirit magic, but will not respond to conventional medicine at all. Insanity caused by overwhelming passions - apparently a serious epidemic among the heroes of romances - can be cured instantaneously by the Path of Passions, and might respond to psychotherapy. Psychological conditions respond well to psychotherapy, and to some degree to the Path of Dreams. Medication and most forms of magic are formally useless - but if the patient knows about them may produce a cure anyway by the placebo effect, working not through their virtues but because the patient believes in them. Organic brain damage and biochemical imbalances are also responsible for some types of insanity, though there are often complicating psychological factors as well. Organic malfunctions are best treated through medication, surgury or the Path of Health.
Another disadvantage often attributed to possession, where the second personality is in fact another soul occupying the same body. It is also sometimes possible to have a second personality which is another aspect of the same soul - a past life reincarnation.
A character with this disadvantage lacks free will. The GM completely controls his actions. Obviously if you take this in its base form, your character is an NPC and there isn't much point in attending the game. It is sometimes appropriate for split personalities, alternate forms or in combination with limitations though.
You encounter a specific type of situation with remarkable frequency. The situations are never immediately fatal, and often you are not even committed to becoming involved, but they certainly can be inconvenient. At the -5 point level this is mostly an excuse for the GM to toss you adventure hooks - the currents of the universe just seem to bring you to these things. At the -15 point level the situations actively follow you around, and are much harder to ignore.
As an example of the difference consider that classic crime drama disadvantage Murder Magnet. At the -5 point level you often discovers the bodies of total strangers, and occasionally get to witness murders at fairly close range; you always get tapped to write the crime report the week of dramatic murders; or your detective agency handles more mysterious death cases than evidence collections for divorce trials. At the -15 point level on the other hand people commonly die within hours of meeting you, your missing pocket knife will turn up through somebody's heart before morning, and when you go on vacation, people routinely stagger in and expire on your hotel room carpet after gasping out a cryptic word or two.
This may be combined with Serendipity (CI 30) if the situations are often beneficial. For example with Serendipity combined with Murder Magnet you will probably spend a lot of time explaining to the police where you were when your worst enemy was dismembered by a crazed serial killer, and that you didn't even know you had an Aunt Agatha, and certainly didn't poison her for the million dollars she left you.
This cost structure applies to Weirdness Magnet as well. Many people play it as the -5 point version with Serendipity and still take -15 points for it. Any disadvantage worth -15 points ought to be near a severe problem, not annoying and occasionally useful!
The basic skill of any magician is Ritual Magic. I take the view successful workings depend more on focused will and sincere intent than the precise ritual and divide magic into two skills. In worlds where magic works for anyone as long as the words are perfect, replace these with a single (IQ/Very Hard) Ritual Magic skill with no defaults between traditions.
Despite its common use in earlier GURPS sample characters, this skill did not exist historically until late in TL5. In earlier periods there was little chance you could transport the sick any real distance, and the idea of learning just a little medicine with the intent of handing the patient to an actual physician would seem peculiar at best, and likely irresponsible. Anyone with real medical training should buy Physician. Most of the techniques we associate with First Aid are recent developments, even things like pressure bandages and artificial respiration are TL6, even keeping wounds clean is a TL5 innovation.
Paths are areas of magic analogous to Colleges in the GURPS Magic system. Rolls to produce magical effects are made against the Path skills of the magician. Voodoo limits Path skills to Ritual Magic, but I would not. Not all traditions force magicians to be generalists. Voodoo also applies the rule of 20 to defaults from Ritual Magic, limiting defaults to 14, and I would keep that.
I prefer a standard set of Paths, but it is possible to argue each tradition should have a unique set. If you do divide the Paths differently for each tradition, make sure there are about the same number, or traditions with fewer will be more cost effective. I do recommend a larger number of Paths than Voodoo, 8-15 seems a comfortable range.
Physician skill is the practical art of healing the sick and injured. At early tech levels the TL division of the Physician skill is inappropriate. I recommend a single Low Tech Physician skill for all effective healing methods prior to TL5, and note in a world with a different history it is possible to practice TL5 or early TL6 medicine any time after the discovery of textiles, pottery and bronze tools. Note there is a myth that the quality of medical care fell during the European Middle Ages, but this not true for most people. The village midwife and the monastic infirmarian continue to practice the same Physician skill they always have, it is merely those who could afford for fashionable care who were treated by Doctors who practiced some less effective Medical Lore skill.
In many cultures and traditions where poisons are a common mechanism of dealing with enemies, a distinction between a natural poisoning, a supernaturally produced but naturally administered poison and an evil spell does not always exist.
Rituals are effects the magician can try to produce - spells if you like. Specific rituals can be improved as maneuvers once you have some points in the Path skill. Rolling for a set ritual from a Ritual Magic default may look like a double default, but is not really and is allowed.
The listed rituals by no means exhaust the possibilities. In the standard system if the magician wants to do something not covered by an existing ritual, have the player write one, compare it with these examples to assign a difficulty modifier and let him use it at that default. The alternative, constraining the magician to spells he has practiced, will give a very different feel, but appears workable.
Voodoo charges two points per +1 to a Ritual; but maneuvers are more consistent with the rest of GURPS, and the difference is only one point. Voodoo caps rituals at Path skill, but I can see a case for allowing at least a little past that (to cancel penalties) and capping the actual skill roll.
The ability to work magic in a particular tradition. You must specialize in a tradition (e.g. Kabbalism, Wicca, Voodoo) but the principles are similar enough to allow you to improvise in another and hope for results.
The Ritual Magic skill is all you actually need to work magic, but it pays to specialize; see Paths and Rituals.
Often used by spirits able to control their ectoplasmic form
You are familiar with the magical forms of a particular tradition. On a skill roll, you can determine what a ritual is intended to accomplish, what entities it invokes, or what the symbols mean. It is common for people to have this skill and not be able to work magic.
Religiously based traditions also default to Theology [tradition] -2. In secret magic settings replace the IQ-6 default with Occultism-6.
You are familiar with the beliefs, traditions and ceremonies of a faith and can at least appear to be a pious member of it. Rolls against this skill are appropriate to recognize cult icons, quote scripture and so on.
The default is to your childhood faith.
The practical skill of changing someone's personality. The name applied reflects social opinion of the changes involved, the actual methods of charismatic cults and Alcoholics Anonymous, or terrorist cell indoctrination and workplace motivational programs are quite similar. Game mechanically this skill allows you to add or remove psychological disadvantages. Decide on the desired change and determine the absolute number of character points involved. Three hours a week of direct contact allows a success roll to accumulate 1/2 character point toward the planned change, nearly constant contact allows the same roll to produce a full point. If the patient is not cooperating, substitute a quick contest with his Will for the success roll. A critical failure negates any previous on this particular disadvantage.
The essential technique is a personal focus on the target - often offers of friendship, flattery and real personal help. It helps considerably if the target can feel part of a socially cohesive group, since the changes can be presented and reinforced as group behavioral norms. Funny haircuts and robes are standard for cults; self help groups generally have to make do with nametags or membership pins.
Other useful techniques include requiring snap decisions (the meeting tonight is perfect for you, I have them on the phone, should I tell them we are coming....), guilt induction, revision of personal history by repeated retelling (soon all the stories in the group have the same motifs), undramatic light hypnosis (by repeating mantras, storytelling by a charismatic leader, or just focusing on a particular point in space), indirect direction (the guru doesn't give me orders, I just know what needs to be done...) and positive reinforcement.
Physiologic changes that can be used as positive reinforcement by reframing them as signs of successful spiritual changes are very effective. Hyperventilation (easily produced by chanting, singing or yelling), repetitive movements (group clapping, rhythmic dance), dizziness (spinning around), and changes in light levels (sudden light after sitting in the dark for the inspirational filmstrip) work well. Poor diet, either deficiencies or actual hunger, can produce both reframable effects and actual changes in brain chemistry; and even a sudden shift to an equally healthy diet like properly balanced vegetarianism produces physiological changes. Sleep deprivation and hard labor are effective, but limited to extreme applications. Drugs are often more acceptable. Many people will not even think of some of them as drugs - sugar buzzing, vitamin and amino acid megadoses, and of course alcohol, can all produce receptive mental states.
The ability to organize and perform a class of formal or ritual activities. On a successful roll the ceremony goes flawlessly. Normal failures indicate a technical flaw; a skilled observer will notice, but it will normally pass without comment. Only a critical failure is an embarrassingly obvious slip. Note the skill allows you to perform the ceremony convincingly. It does not necessarily authorize you to - Clerical Investment or Legal Authority may be needed for that.
Skill difficulty depends on how complex and varied the ceremonies are. Individual ceremonies are usually Average (e.g. Ceremonies [tea ceremony], an oriental art, or Ceremonies [formal wedding], the professional skill of wedding chapel owners). Groups of related ceremonies such as the daily rituals of a faith (Ceremonies [parish priest]), or political office (Ceremonies [royal court]) are Hard. A large group of complex ceremonies (e.g. Ceremonies [High church] or Ceremonies [Aztec sacrifices]) are Very Hard.
Practitioners of faith based ritual magic can expect to perform a wide range of ceremonies to mark life changing events with strictly spiritual significance - births, namings, initiations into adulthood or the faith, betrothals, marriages, funerals, formal oaths, confessions and absolutions, ordinations, anathemas and routine worship services. Anything with a reliable magical effect should use a Path skill, though if routine rituals like these actually do have a magical effect the GM may want to use the Path of [faith] to cover them rather than trying to force them into the structures above. If they are magically effective the prerequisite may differ from standard magic - Clerical Investment may be required.
Common religious Ceremonies default to Theology [faith] -5 or Ritual Magic [faith] -5; Savior Faire defaults are also common for some ceremonies.
This skill is suited to the theology of fringe cults or the principles of mystical systems built around contradictions, though it could also model deep familiarity with Treknobabble. To anyone not skilled in a particular type of Incomprehensible Lore the 'information' covered by the skill is nonsensical, or internally contradictory, Practitioners of the skill can somehow tell the difference and will agree that it isn't colorless green ideas that sleep furiously. It's colorless pink ones. Colorless green ideas electrify the circular squares in the thoughts of the mindless God hallucination man. Weren't you paying attention when the rabbit skittered the ground loop? Whether this skill is good for anything but in-group recognition is up the GM, in a universe which is fundamentally irrational one of these mystical systems might actually be close to the truth.