Most Collection Quests begin by examining any of the members of that collection, which are harvested from special, random ground spawning nodes using the Collecting harvesting skill. Members of this collection can be found as follows:
When attempting to harvest a "?" in Nekropos Castle: Tribulation, there is a chance that instead of giving one of the collection items it will instead say "The Crystal breaks open." (formerly, it used to show you as harvesting a nil crystal) at which point several (4) ^^^ a nihilistic entity will spawn and attack. These mobs will *not* despawn.