I’ve been working on a village-building based D&D campaign. One of the things I want to do is tie character progression to exploration, and a way to do that is make classes available based on which NPCs the party has allied with or even brought back to their settlement. For this reason, I picked a random advancement scheme, where players roll 1d100 twice on a table associated with their character class to see what they get when they level up. They can choose choose to roll on the tables of unlocked specialty classes, which means they don’t need to roll a whole new character to realize the benefits of making allies and gaining access to new stuff.
Since this model of D&D is based on building relationships and developing a home base, I want making friends to be on the table as much as possible. This class is unlocked by normalizing relations with the Orminger King, the local dragon and source of many monsters incursions (and sagacious-monarch-turned-abhuman-monster). It also complicates the player’s relationship with most normative NPCs while potentially making it easier to seek peaceful solutions with monsters. Moreover, since this is a low HP class prone to drawing aggression while still having some pretty piquant abilities, players will hopefully be dealing with the mix of power and vulnerability that makes the archetypes behind this class compelling.

Also also, it’s a bit of a rough draft. I’m not terribly worried about balance since it’s random and also players need to go to a lot of trouble to make it available in the first place, but it could still be an issue.
Based on: Ganon, Howl, Witch of the Waste, Queen Beryl, Apostles from Berserk, Maleficent, animist wizards, there’s probably some Dark Souls in here if I’m being honest with myself
from full metal alchemist
WARLOCK
Requisites: make peace with the Orminger King
You are gorgeous and monstrous, magnificent and grotesque. Your magic is born from the darkness of the new moon and the blackness in the deepest earth. People think you’re not entirely human, and they’re not entirely wrong–the wilds and the ruins and the lonely places of the world are filled with the monstrous shells of the god-kings and wicked scholars who were consumed by the power you now bear. By its nature, your magic has left a sorcerous mark somewhere on your body: your palm, your tongue, your belly, your breast. In cosmopolitan areas, people who recognize you as a warlock will be discomfited, wary, and very polite. In more superstitious areas, people will be outright terrified of you–maybe enough to do what you ask, perhaps enough to just try to kill you. 

from magi: labyrinth of magic
  • HD: 1d4
  • Saves: as Magic-user
  • XP: as Magic-user
  • Prerequisite: have an emissary of the Orminger King join your village. New characters can be warlocks once the prerequisite is met, but existing magic-users can select it as a subclass.

The first time you roll on the Warlock table, you gain the ability to assume a monstrous aspect at will, giving you +1 Defense and allowing you to deal d6 damage with unarmed attacks. You cannot wield weapons or wear armor, in this form and most civilized peoples will attack you on sight. If they see you transform, they will seek to jail or execute you, even in human shape. Moreover, while you wear your monstrous shape, the Referee may require you to make a Wis check to resist the impulse to do something greedy or spiteful, if a compelling opportunity presents itself. The appearance of your monster-shape is up to you, though your face always remains the same even as your body changes.

Entries in a list separated by slashes show what is available with each subsequent reroll of that entry.

roll
new ability
1-40
+1 Spell Die
41-60
+1 Save
61-65
Your beast form gains one of the following movement types: climb, swim, clumsy flight. Pick another on reroll.
66-70
Your beast form gain skill of your choice from the following list: Track, Sense, Camouflage. Pick another on a reroll.
71-75
Your beast form’s size becomes Large and you gain +1 to Str and -1 to Dex checks. Lose the Dex penalty on reroll.
76-80
Your beast form has armor as leather/chain/plate.
81-85
Wormtongue. Gain a skill of your choice from the following list: Tempt, Deceive, Intimidate. Pick another on a reroll.
86-90
Dark Glamor. At will, you can wrap yourself in a mantle of dark power, allowing you to transform your clothing as you please and making you appear taller, more imposing, perhaps more appealing and perhaps more hideous. In this aspect your have +1/2/3 Disposition Die size from those prone to temptation and sycophancy; -1 Disposition Die size from those who value basic decency and bravery.
91-95
Minions. You have 1/2/3 Level 0 homunculi allies. They are dark silhouettes of humans, suggestive of ooze in the way their bodies give and sway with each motion. If they wear human clothes, nobody will be able to notice that their appearance is strange. If they die or get lost, you can brew one per downtime up to your max. They are very stupid.
96
Covenant. If someone breaks the word of a promise they made to you, they suffer a -2/4/6 penalty on their saving throws against your spells, and you instinctively know their direction and approximate distance. It must be a promise you genuinely wanted kept, and this ability ceases to function if you forgive them for their transgression.
97
All Shall Love Me. +1/2/3 Faction Die size with monsters.
98
Forbidden Power. When you cast a spell, you can choose to roll with d8s/d10s/12s instead. Each die still expends on a result of 4+.
99
Menace. Enemies in line of sight of you suffer -1/2 Morale.
100
Dark Garden. You rule a 1 acre demiplane that contains your lair. Its appearance is a matter of negotiation between you and the Referee. It can house and feed 1/2/3 people per day. It is totally inaccessible, but if you spend a long rest in a civilized place, you can choose to incorporate the gate to your demiplane into the location in such a way that even longtime locals may not notice it. If you close the gate to your demiplane from the outside, you can choose to send it away again. Anything native to your lair taken out of it vanishes into thick black smoke as soon as it crosses the threshold.

from spirited away
THE ORMINGER KING

A man’s impassive face, pale and immense, set onto a black-furred body, sinuous, graceful, larger than an elephant, walking on the fingertips of splayed human hands. Its great wings are like a crow’s. It is mad, mournful, vicious. It lives in the ruins of the Royal Archives, gently turning pages with giant fingertips. It brews and decants shadow-fleshed homunculi to send on raids for occult reagents and, once in a rare while, companions. It knows many spells of darkness and transformation.

RULES
I draw on some homebrew rules in a few of the entries, so here are explanations:

Magic

You can cast any spell you know. You have a number of Spell Dice, a pool of d6s which represent a combination of your innate magical affinity and experience with your craft. With more Spell Dice, you can cast more powerful spells more often. When you cast a spell, roll any number of your Spell Dice. Examine the result of each die and add up the results. Dice that come up 4+ are expended, and you cannot roll them again until your take a long rest.

from howl’s moving castle
Reactions/Personality Dice/Disposition Dice
The Referee makes Reaction Rolls on the usual table. However, they are not necessarily made with the traditional 2d6. One die is the Faction Die, and represents the encountered creature’s relationship with the organizations, groups, species, clans, etc the party or party leader is a member of. The other is the Disposition Die, which represents the encountered creature’s gut reaction to the party or party leader, a combination of the PC’s personal appeal and the creature’s mood. Both dice start at d6 and are increased by factors that would improve reaction and decreased by factors that would worsen it. Some characters have explicit bonuses to one or both dice, but the Referee can also apply modifiers ad hoc. Example: A handsome cleric wandering a dungeon encounters an incubus. The Referee determines that the Faction Die should be a d4, since demons find clerics tediously Lawful. The Disposition Die, on the other hand, is a d8, because incubi respect physical appeal.
from sailor moon