Can Hypokeimenon be a predicate?

 Despite being of sound Mallu stock, Kay Kay Menon's nephew, Hypokei Menon, in the opinion of Aristotle, can't be a predicate of anything. Does this represent a damning indictment of Kerala's education system? No. If there is an underlying substratum, what is the grid to which it sticks? Spinoza might say there is nothing but the grid, just that one substance. But either Spinozan substance has only one possible way of existing or it doesn't. In either case it becomes a predicate of whatever it is that designates its  trans-nomological modal possibility. Anyway, that's the plot of Hazaron Kwaishen Part II- Return to the Planet of Naxalbari Apes.