I've cleared HM Crota a ridiculous amount of times. I've gotten about 50 helmets, too many Word of Crota + Fang of Ir Yut to count, a countless assortment of random exotics, and 5 cruxes, whatever they are, but still no Nechrocasm! I have everything else I need from him, do I just dismantle everything I get now. How rare of a drop is this bad boy from him? I'm starting to lose faith.