I just had the same problem right now. I got a weapon and gauntlets on Oryx first time without Moldering Shards... Second time, i had 20 and only got 1 weapon. Like really? Description says, "Extra rewards WILL be granted when defeating Oryx in the King's Fall Raid with at least 20 of these." I had 20? The description needs to be changed for better accuracy or maybe it's just not working as planned. Just sucks that i had to do all that farming for flakes so i could buy enough moldering shards to reach 20 and i got nothing out of it.