I have used about 20 rubies and have not seen elemental crit damage (blight) all my items are poison and haven’t seen ignore resist. Is there a way to dial in more of what I want? I keep getting 4 procs minimum as choices and it is getting annoying. I am 5 slots away from finishing my summon gear. Please if you have any strategy, let me know! Ty
All about luck 
This same sorta thing is happening to me where I cant seem to get blight from ruby or torrent but I will keep trying. As dieter said: All about luck.