Assassin's BiS (Best in slots)

Hi! I know that I need to keep upgrading all the Hongmoon stuff but my questions are about:

GEMS: I'm currently using Damage Ruby, Drain Amethyst and Defense Diamond, is there a better setup? Are the blue pentagram the most powerful?

SOUL SHIELD: What's the strongest now for PvE? Blackram Supply, Bloodshade or Endless Tower? What do I have to use to upgrade it?

UNKNOWS SLOTS: Bracelet, Belt and Soul are supposed to be empty?

BUILD: I'm using the Dungeon Lightning and that's what I want to keep but are there some improvements I can make from the standard build?

Thanks for any suggestion.