Just replicating a post from another thread, since this one seems to be more focused on speculation:
I find it unlikely that the pack will include more than 1 supernatural (witches). But witches vary so much according to lore and culture that I think many other supernatural beings can be covered if they create a wide array of skills and invest in customization, as someone said above.
Ideally, I’d like magic itself not to be restricted to a certain type of sim, but to be a skill, or a set of skills that come in different varieties and evolve in different ways.
So, for example, progress in the alchemy path could, aside from enabling the sim to make more powerful potions/elixirs, unlock certain abilities as you level up, such as conjure up raw materials, turn an object into another, turn a sim into a frog/rat/whatever, bring a dead sim back to life in exchange for another sim’s life, manipulate lifespans by transferring days of life from onde sim to another, etc. The sim would level up through the routinely usage of the skills and the creation of a certain amount of elixirs/potions.
Progress in the “academic magic” path could unlock more traditional skills, such as levitation, teleportation, curses and blessings, mind reading, bending another sim’s will, etc. The sim would level up through the study of plenty of books and constant skill usage.
Progress in the “natural magic” path could unlock elemental magic (fire, ice, lightning, meteors, earthquakes, growing plants, etc.) and maybe enable more interactions with animals, allowing the sim to call them forth or talk to them. The sim would level up through constant skill usage and different activities related to the elements, such as going out in a storm to be hit by lightning, interacting with X fireplaces or standing through a heatwave outside, going out during a blizzard, fishing, swimming, hunting for collectibles, making snowmen, interacting with plants and animals, etc.
I think around 10 skills per path might be enough (vampires had 25 in total I guess, so 30 is not unrealistic, specially considering we’re talking about witches here).
All these paths could also be just different branches in a single skill tree.
I think this system (or something similar to it) would be a nice way to give each sim a unique experience and it doesn’t seem unfeasible for a game pack.
As for the world (which I hope accompanies the pack), I’d like a mountainy landscape with a few castles (5 lots would be fine, like forgotten hollow, as long as there’s a wide public area around them full of nice details to explore).
In regard to items, I’d appreciate lush outfits and furniture for the local nobility. And of course, some rags for the peasants.