Fomoria is more like giants with glamoured troops sprinkled in

They are an air/death nation with some water/death minor, big sacred giants, and some cap-only recruitable glamoured troops (which are not sacred, excepting the nemedian champion). Anyway the entire point of the suggestion is to be as helheim-like as possible without being helheim. At least magic-wise. You could always go for vanheim if you were going for the glamour angle. Or TNN.