This is an idea I've had for a "Dying Earth" campaign.
Wizards of Ryxys are shrouded in mystery. A child who has a natural inclination for magick may undergo training in the Crystal Halls of Ryxys (originally a crystal asteroid that had crashed and then later was discovered this was actually a space craft). Once the training is complete, the magic user is given the robes of Ryxys (they believe the Wizards must be covered head to toe to preserve their magical energies, if their body is exposed they'll lose mana), and set upon the world to search for artifacts of Ryxys that can shed light on the magic contained within the craft.
I'm using regular rules for Magic Users (except they can use weapons) in The Swords & Wizardry Core Book, but maybe I'll come up with some newer spells.