Realm of Magic SimGuru/Maxis-Sourced Info

As your Sim gains more experience and fulfills aspirations, they'll also earn Talent Points. Use these Talent Points - wisely, my friends - to choose Spellcaster Perks, which can increase your Sim's magical prowess. Will your Sim choose a Blender Arm for speedy potion-making or Spectral Reach to cast spells anonymously from long distances? Once their magical powers improve to advanced levels, they can become a Master Duelist or select Potent Potables for lasting potion effects. - blog

Sages are very important in The Magic Realm. There is one sage for each house and they each hold the keys to your Sim learning different kinds of magic. Chat with all three and even become friends with these masters of sorcery. They can teach your Sim magic, school them on Spells, and join them in a friendly duel. Sims can also learn new Spells and potion recipes from reading Magical Tomes or by Practicing Magic. - blog

Practical Magic
Spells learned in this school help Sims with all things helpful and useful. Transportalate teleports Sims to other places without that pesky travel time, Repairo fixes broken objects or makes crafted objects higher quality, and Floralorial keeps plants healthy and bug-free.

Untamed Magic
Untamed Magic is for Sims who want the wildest Spells in their wheelhouse. Chillio causes a blast of cold air that freezes any Sim it touches, Necrocall summons the dead from their final resting place, and Minionize controls another Sim's mind!

Mischief Magic
Does your Sim love tormenting others? Mischief magic is for them! Learn Despario to make Sims sad, Deliriate to scramble a Sim's thoughts, and Furio to convince Sims to argue and fight with each other. If that's what you're into, yay!

Alchemy
Once your Sim picks up supplies at Casters Alley, they'll be on their way to creating some intoxicating concoctions. They'll also need a cauldron, of which many can be found in The Magic Realm. Or, for some home brewing, purchase a cauldron for your Sim's house. They can experiment or - obviously - cook mac and cheese with these massive vessels- blog

Collect and cast spells to make Sims fight, conjure food, or even turn others into objects. Create drinkable potions to make Sims fall in love, remove unwanted curses, or live forever! - EA

Crystals are one of the main ingridients for potions and they’ll be required for higher-level potions.... Up to 4 Sims can be brewing up a potion at the same time.- SimsCommunity Livestream Overview

Removing Spellcaster powers from your Sim will also get rid of all of the curses that you’ve obtained while being a Spellcaster. However, there is a cooldown period that you’ll have to wait until becoming a Spellcaster again so that this feature doesn’t get abused for getting rid of curses easily.... You can have up to 3 curses at the same time. There are 10 different curses in the game. - SimsCommunity Livestream Overview

Any time you want to track your Sim's progress, click on them to open their trusty Spellbook. Every incantation, ritual, and elixir a Spellcaster has learned is recorded here. It's also pretty freakin' cool that your Sim will have a Spellbook now.- blog

Removing Spellcaster powers from your Sim will also get rid of all of the curses that you’ve obtained while being a Spellcaster. However, there is a cooldown period that you’ll have to wait until becoming a Spellcaster again so that this feature doesn’t get abused for getting rid of curses easily.
... There’s a Spellcaster Charge in the Needs Menu that shows the Magical Energy of your Spellcaster. When clicking on the Spellcaster Charge meter you’ll be able to find out how filled your Magical Energy is.
Overcharged Magical Energy can give your Sim negative moodlets that can also lead to death by overload if there’s too much Magical Energy.- SimsCommunity Livestream Overview