Well, I did some more planning and thinking, and here's the results.
Basically, the spells would be created from special ores. You could either mine the ores, or buy them. Then, you would basically take it to the "Ore Master" and get him to combine ores into spell rocks. Spell rocks are ways to concentrate your mind and release power. Different combinations of ores will result in different spells, but some ores won't combine at all.
There would basically be 4 types of ore. Blue ore, Red ore, Black ore, White ore. Here's a sample chart of ore mixing:
NPC Code:
Blue
\
--------- Ice Shield 1 / Blocks arrows, takes 15 SP.
/
Blue
Red
\
--------- Haste 1 / Increase speed, takes 3 SP / 2 seconds.
/
Red
White
\
--------- Mend Body 1 / Heals one heart, takes 10 SP.
/
White
These are just the non-offensive spells. Also, you might notice the "1's" beside them. There is a way to change it to a 2, however. Combining rocks.
When you make two blue rocks for Ice Shield 1, take them to the "Rock Master" and get him to combine them, for a price. This will basically give you an improved power rock with Ice Shield 2 inside of it. The same goes for the Haste spell, Mend Body spell, etc.
SP is basically "Stone Power." Once you get a stone, you can power up your SP by getting a concentration stone. When you use it, you go into concentration mode, not moving or attacking, but standing still and gaining SP every 2 seconds. If you move, you'll stop the concentration mode.
The 2 Power spells have added bonuses. Haste 2 will make you run very quickly, Mend Body will heal you 2 hearts, Ice Shield will block fireballs, etc. They'll cost more SP, however.
If you're hit while casting the spell, or moved, you'll be interrupted, and nothing will happen.
Below are some of the ganis I have made for the non offensive spells. I'd add script to them, but I'm horrible at scripting. Anyone's welcome to take a shot at converting them, though.
Well, there's my idea. Please read it with consideration. Thank you.