So, now that the glittery shots out of the way, this is how it would work...
You choose the spell you wanna create, but you wouldn't make a new spell, it would just be a branch of that spell ( Let's use the fire spell for example...)
You then select the damage of the spell using a power source of some sort (like a soul stone) and the blast radius or such and such
That's your new spell, EXCEPT... You now get to use a different power source to add effects to that spell! ( like a rune or something cool like that, eh?)
That rune would need to be infused with that element or idea (elemental runes are kind of a given) but things like frenzy and rally are something I havent really thought of
You can add four runes to that spell ( determined by perks) and then you name your spell! You can also edit the color of the aura or element in your spell ( pretty nifty huh?)
When you go to select that spell, you would click on your fire spell and a little window would pop up! You cab choose your created spell, or the normal fire spell :3
How many created spells you can have at once or in one spell category is obviously determined by... Drumroll please... PERKS!!!
DISCUSS!!!
Sorry for any spelling mistakes, on me iPod.