Expert Collector of Black Assassin Gatekeepers Expert Collector > Page: 34 Acquiring Req.: Collect at least 50 Black Assassin Gatekeepers. Reward: When collecting Black Assassin Gatekeepers, the Collectable Item is doubled. Black Assassin Gatekeeper Lv 40 Black Assassin Gatekeeper's Natural Enemy Natural Enemy (31-40) > Page: 20 Acquiring Req.: Kill at least 90 Black Assassin Gatekeepers. Reward: Killing Black Assassin Gatekeepers grants you bonus XP. Black Assassin Gatekeeper Lv 40 Legendary Black Assassin Gatekeeper Hunter Natural Enemy (31-40) > Page: 20 Acquiring Req.: Kill at least 210 Black Assassin Gatekeepers. (Black Assassin Gatekeeper's Natural Enemy Title is required.) Reward: Killing Black Assassin Gatekeepers grants you bonus XP. Black Assassin Gatekeeper Lv 40