One thing I want to check: In order to cast fire, is it intentional that you have to do something else first? That something else will be left ambiguous if you don't mind
EDIT: I found what I was doing wrong.
the "something else" was a PUT command, but now I realize the issue was with the order of drawing, which is really finnicky for some reason. Generally you can only draw a sigil from one starting point and going in one direction from choices. Is there a puzzling reason to this input sensitivity I haven't understood yet? I hope there is, because there's a lot of "partial sigils" where I draw a picture that's intended as a hint because it looks right, but I don't get the hint unless I draw even that sigil in the right order.