Ghost Hunter equipment has a set bonus that increases experience earned and damage done against ghosts and related creatures. This bonus is 3% with one piece, 6% with two pieces, and 10% with three or more pieces of the set. Since the Hallowe'en event ended, it can now be obtained as a rare drop from ghost type monsters, such as aberrant spectres. This armour can be stored in the armour case of the POH. Make sure all four pieces are the same level by wearing them all because they won't store if different levels.