I tried out a DG Shaman today to figure out what I'll be doing on Oct 1. The starter quest from the NPC by the trainers took a very long time to complete - from what I was able to determine, you have to use a salve on mushroom dudes in the cavern and then kill them (before the buff wears off) to get a special drop. You need 4 of these drops. However, from my experience, it seems only the "sickly" mushroom guys drop the quest item, and one issue I ran into is that the cavern only has around 15 mushroom guys in it, and just 3 or 4 of them are of the "sickly" type. Are there more of these mobs somewhere else? Another baby Shaman went to the newbie killing area and didn't see any potential mobs there. A secondary issue I ran into is that since Shaman killing is so slow in the early game, the buff actually wore off once before I was able to kill the mob (and it's not possible to re-apply the salve since the mob keeps interrupting you).
Unless there's a giant supply of these mushroom dudes somewhere I think this quest will be impossible to complete if more than 2 Shaman are competing for mobs - there's just so few of them and the spawn rate is so low. My suggestion is to add a lot more of the target mobs and spawn them more quickly.