Technically, you are a goat and some followers, but we'll get to that in a minute.
You are a very bad goat. You're not a demon or a devil or an evil spirit. See, goats are naturally filled with a bit of evil and cunning, just like sheep are naturally filled with a bit of good and stupid. It's just the way the world was made. Goats act like lightning rods for wickedness. If enough wicked, small-minded, cruel, power-hungry, miserly, and sinful people die in a given area, bits of their souls get trapped in a goat. They go to the afterlife with slightly better chances.
In most sensible communities, these wicked lightning-rod goats are driven away or ritually killed, but people are forgetful and goats are valuable and sometimes things get out of hand.
Side Note: in some very good communities, the opposite effect applies to sheep. They get a little bit of virtue. It has no significant effect, but it does explain why wool sweaters occasionally, against all odds and in defiance of accepted traditions, ward off vampires and ghosts.
So you're a goat full of spare soul fragments and wickedness and all the petty cruelties of a community. One day, you realized you could think. Not long after, that you were smarter than most of the humans you've seen. And soon enough, that you could influence the world in dangerous ways.
A: Goat, Dark Powers, +1 Witch, 2 Spells
B: +1 Witch, +2 Spells, Goatly Phasing
C: +1 Witch, +2 Spells, Dark Ritual
D: +1 Witch, +2 Spells, Dark Majesty
I pray for the GM who allows you to multiclass, for I will not.
You are a goat. Do not roll for your race. Reroll Dex. at character creation and pick the higher result. You suffer no penalties for moving over broken or hilly terrain.
Generate your stats normally except for HP. Your HP is always 8 and will never increase. You cannot wear armour, carry items (a backpack would be beneath your goatly dignity), or manipulate things beyond kicking (d4 damage), goring with your horns (1d6 damage), or nipping (1 damage). You get 1 attack per round.
You want luxuries and power. Your ideal endgame retirement plans might resemble an opium den crossed with a silk merchant's warehouse and a brothel.
At will, you can speak into the mind of a suggestible person. Strong-willed people will hear a faint buzzing or hissing. Your witches can't help but year you. You can only speak to one person at a time, as an intimate whisper.
Once per day, you can:
-cause a minor horrible omen to appear. Statues weep blood, ashes spell out "DOOM", a bird falls out of the air dead, small children sing eerie songs, etc. Can't deal damage or provide some handy secondary benefit, like triggering a trap, but it will probably scare the bejeesus out of someone.
-appear to grow as large as a horse for 1 minute. You can only do this in dim light. It's clear to viewers that this is a trick of perspective, a horrible hallucination where your form grows larger or their perspective warps.
-appear as a naked goat-headed humanoid for 1 minute, with all the usual infernal accoutrements.
You gain a witch follower (traditionally a woman but there's no strict restriction) to a maximum of 4 witches. Women in medieval societies are typically the easiest people to tempt with revenge, power, and the good life. Roll on the Horrible Peasant NPC generator for a name (use 50+d50), a distinct odour, appearance, and disposition.
A witch has the following stats:
Morale: 6 or 8 if you are standing next to them.
1 attack per round dealing 1 damage (punching/hitting things with a stick).
4 Inventory Slots
1 Magic Dice and 1 Spell Slot
Witches use your Save and your Wisdom for initiative. Witches can pool their magic dice to cast spells. To pool dice, they need to be within 10' of each other. They can commune with your goatly majesty for 1hr to move spells from your hideous frothing mind to theirs. You're their spellbook, effectively. All witches count as 1 character for the purposes of concentrating, initiative, etc.
Attacks that target "that lot over there" or "the damn goat" will always hit a witch before it hits you, provided you are within 10' a witch.
If a witch dies you take 1 damage. If you still have at least 1 other Witch, you can recruit replacements after 3 days in a populated area. If all your Witches are dead, it takes 1 week to get 1 Witch back, plus 3 days for the rest of them. This might mean you're unable to cast spells or affect the world for a week, so hopefully you take good care of your followers. You also gain a Witch (to a maximum of 4) whenever you level, even past level 4. They just turn up. Maybe it's fate.
Witches are like hirelings. You control them, but the GM gets to see if they run from danger, panic, fail at their tasks, give up, or do unhelpful peasant things. In dangerous situations, they won't move more than 10' from each other without a Morale check.
Side Note: proper witches, who got their power all on their own, think goat-bound witches are deluded and weak. They're right. On the other hand, because you're a goat, chances are good your witches will spend money like water and live excellent decadent lives (and you'll live through them, vicariously). If a proper witch catches you, she might use you as a mobile spellbook and magic reservoir or she might make you pull her around in a cart.
As long as you have at least one Witch, you can choose to stop existing. You're... elsewhere. The process takes 1 minute and requires deep shadows or total darkness. You fade with just your red eyes visible. You can't fade if you're being attacked, if you're falling, etc. You can fade back in with the same limitations. You walk in from the shadows, from behind a tree, from tall grass.
While faded, you can see and hear through the eyes of your Witches and sense their emotions. You can still speak to your witches, but you can't use any of your other Dark Powers.
Once per week, at night, you may lead your Witches in a ritualistic dance. You can do this every week but you probably shouldn't. Save it for times when you might really need extra power. You need an isolated area: a hilltop, a meadow, a basement, a ruined tower. Make up some mystical stuff about the full moon and the stars being right if it gets your Witches in a proper mood.
The ritual takes 1hr and must involve some boundary-pushing act for the Witches. You don't need to go into detail (please don't go into detail), but in general:
1. the first time the Witches do the ritual, just doing it will be enough.
2. the next time, doing it naked will be enough.
3. the next time, doing it naked and sacrificing a small animal will be enough.
This resets if all the Witches die.
If the ritual is interrupted by an outsider, it fails if the interloper lives past sunrise.
The ritual adds +1 MD for each Witch that participates (up to +4 total) to the next day's casting pool. No more than 5 MD can be used on any spell. In addition, for the day, the Witches can cast any spell you know as long, as you are present, without having to spend 1hr communing with you.
While you are present, your Witches have a Morale of 10. If you choose, one Witch will obey your whispered commands mindlessly, without fear or self preservation. The other Witches might not like this but they're hardly in a position to do anything about it.
SpellsRoll 1d12 randomly each time you gain a spell. You can't learn Wizard spells from spellbooks unless they're dark and weird. Your spells aren't witch flavoured, they're goat flavoured. Subtle difference, but it annoys actual subtle witches.
1. Telekinetic Shove
R: 50‘ T: creature or object D: 0
An object or creature within range is hurled through the air. Save to negate. A human-sized creature travels 10’ per [dice], and takes 1d6 damage for every 10' traveled. A creature thrown at another creature requires an Attack roll to hit and inflicts 1d6 damage for every 10' traveled. This spell will also blow open all the closed but unlocked doors in a room, shatter all the windows in a building, or knock the thatched roof off a peasant's shack.
2. Limited Flight
R: touch T: [dice] creatures D: [sum] minutes
Target creatures gain a fly speed equal to 2x their movement for the duration of the spell. Up to 4 witches count as 1 creature provided they hold hands or ride on broomsticks.
R: 50' T: creature of [dice]x2 HD or less. D: [dice] hours
Target creature regards you as a good friend. Save negates. If you invest 4 [dice] or more into this spell, the duration becomes permanent. They will, in a slow and dopey semi-aware state, obey any requests that do not directly harm them. When the effect ends, they will realized they've been bewitched. If you made them do anything embarrassing or harmful, they are immune to future Bewitching.
R: 50' T: mortal creature D: permanent
You inflict a Minor or Major curse on the target. For a minor curse, you must invest 2 [dice]. For a major curse, you must invest 4 [dice]. Dice used to cast this spell are automatically exhausted. You cannot dispel your own curses. Example curses are listed here.
R: 50' T: creature D: concentration
Target feels cold. If you invest 3 [dice] or more, and you loudly pronounce doom on them for the next 2 turns (without being interrupted or breaking line of sight), target dies on the 3rd turn. You need to truly hate the target for this spell to work, or convince yourself that you hate the target. Even a sliver of pity cancels the spell.
6. Goat Fog
R: 30’ T: self D: [dice] hours
You breath out a bunch of fog. Everything up to 30' away from you is obscured. Sunlight, wind, or heat dissipates the fog in 10 minutes. If you cast this spell with 3 or more [dice], other casters lose 1 MD while they remain in the fog. The fog smells like goats, oil, and sweat.
R: 50' T: creatures up to [sum] HD D: 0
Target creatures must Save vs Fear or take a morale check, or flee from you. If you cast this spell with 4 [dice], creatures unused to supernatural occurrences (peasants, domesticated dogs, etc.) must also Save or age 2d10 years.
8. Hold Person
R: 50' T: creature D: concentration, up to [sum] rounds
Target creature is locked in place. You must maintain concentration for this spell to work. Target can breathe and move their eyes, but cannot swim, fly, or perform any other action. If the creature is particularly willful, blasphemous, or a spellcaster, it may Save each round to break free, with a penalty equal to the [dice] you invested.
9. Spontaneous Generation
R. touch T: object D: 0
You hand another creature a nonmagical object. They must willingly take it from you. The maximum size of the object depends on how many dice are invested in the spell: 1 [dice]: pebble-sized, 2 [dice]: grape-sized, 3 [dice]: bucket or helmet-sized, 4 [dice]: person-sized. Up to [sum] rounds later, at a time you chose, the object permanently turns into vermin: maggots, spiders, centipedes, and slime. The creatures aren't hostile or venomous, but their bites itch and they probably don't want to be held.
10. Cure Light Wounds
R: touch T: creature D: 0
Target creature heals [sum] HP. It costs 2 HP to remove one negative HP. This spell cannot remove Fatal Wounds, cure diseases, or heal lost limbs.
11. Illusion of Youth
R: touch T: creature D: [dice] days, or, if [sum] > 12, permanent (until death)
Touched creature is cloaked with an illusion that makes them appear to be in their physical prime. The illusion can be popped with a solid blow.
R: [dice]x1 miles T: self D: [sum] hours
Small glowing lights flow from your fingertips. They are as bright as a match, but you can always see them, even in bright sunlight or pitch darkness, at any distance up to 1 mile. The lights guide the caster to an object, person, or location that they believe will result in the emotional state named when the spell is cast. If the caster names "love", they will lead to the nearest sexually compatible person of similar age. If the caster names "joy" they might lead to a well of nitrous oxide, or to a pile of treasure, or to a crude goblin joke scrawled on a wall. The lights have a dry sense of humour.
1. MD only return to your pool on a 1 for 24 hours
2. You, the goat, take 1d6 damage.
3. You, the goat, and your witches take 1 damage.
4. One witch spends 1d6 rounds screaming, twitching, and frothing.
5. Nearest faithful and sensible NPC who is not aware of your coven becomes aware of your coven.
6. Spell targets you (if harmful) or enemy (if beneficial) or fizzles (if neutral).
Witch Coven Dooms
1. One witch dies. Messily.
2. All your witches die. Lots of screaming and wailing and bursting. Nearest faithful, sensible, and powerful NPC who is not aware of your coven becomes aware of your coven.
3. A wrathful team of 1d10x10 demons, angels, inquisitors, bishops, and peasants all arrive at once to put an end to your wretched life of vice and crime. While they hunt you, you cannot use your Goatly Phasing ability.
Mechanical Notes on the Witch Coven
It's a complicated class. Possibly impractical.
It might seem overpowered. It's got most of the benefits of a wizard and a few more on top. The core downside is that you're trying to manage up to 4 NPCs (with bribes, threats, promises, etc) to do your goatly bidding. Hopefully the GM will make that interesting and give each witch a useful personality.
Also, you keep stealing people from villages. That'll eventually cause trouble.
Also, people want to burn your coven. If they're smart, they'll burn you too.
Also, without witches, you're just a goat.
If you're going to use this class, consider not including wizards in your game. See how it goes.