Well first of your question is vague at best but I think I got the answer, there are two sets with the word Imperium in it Brands of the Imperium and Wrath of the Imperium. Wrath is a set with 1 staff and 2 rings and can be found through the PvP reward of the worthy or through PvP vendors. Brands of the Imperium is a 7 piece heavy armor set that you can only get by doing the new Dungeons in the Imperial City. Normal version of the dungeon gives v15 and Veteran gives v16, due note the spawn rate on those are very low. So there you go, try and be more specific in your question next time.