Holy Glory set is a 6-piece set that can be obtained through crafting (weapon) and as a Secret Dungeon reward (armor). It has a 14 day limit when obtained in Casual mode and is permanent when awarded in Hardcore mode. It has a high chance to be looted whenever the player opens all 10 chest in Secret Dungeon, but there's a smaller chance to drop Dark Angel Set instead, which is quite similar to HG. (Holy Glory).
HG set as it looks like when equipped (Glaive of Smiting not included).