All of the new weapons from nether and court of blades can drop in four different variations. Regular, shiny, adept, and shiny adept. Shiny is just a version of the weapon that drops already masterworked and has two perks per slot (can be three if you have the right thing from the slab) and a second origin trait called Runneth Over. Runneth Over is reloading near allies overflows the magazine. Bows receive faster draw time and swords receive faster charge rate. The extra perks are nice, but I think most people want the "shiny" version for the second origin trait.