So I'm thinking of ways to do transformation spells, the sort of thing that would happen in the old game when you made a tattoo filled with various substances and then became all or partially made of those substances. They, along with "control" were pretty OP in the original game, so I'm thinking of a way to limit their usage a bit.
Now, enchanting things currently works by writing the words on whatever you want to enchant. For instance, write the word for fire on your sword to get a fire sword! Write flesh kitten chainsaw on your sword to cause it to cut like a chainsaw made of a thousand little kitten claws. Basically, it doesn't transform things into other things, it just gives them aspects of those things.
Now, for transformative spells I was thinking that it would be the same as enchanting, except that instead of just writing or drawing or engraving the words, you have to inscribe the word or words on a piece of material and then physically implant it in whatever you want to transform. Ie, to transform into steel, you would need to get a steel stud or something, engrave the word for steel on it and then jam it into your flesh. Transforming your whole body would require lots of these "piercings" and it would prevent people from just willy nilly transforming themselves into steam or lightning or toxin. You'd have to plan things out very carefully, transforming in stages and using solidified forms of substances. You could also, say, implant a steel rod with "Steel sword" on it to transform that limb into a steel sword. etc.