My Dk will be AK 4 just before this boss goes away. So, if I kill the boss now for the loot, then come back later and kill them again for the Hidden, would it drop? I know Frost has only been out today, but I was wondering about the other 'hidden' appearances that dropped from World Bosses, and if anyone had experience with those and how they interacted with 'multi-kills' within the week.