I encountered one last night, I thought I could get a quick low level roulette in for my 49 brd before bedtime and I ended up in Aurum Vale, ugh I thought.. It got worse when the Nin decided he wanted to walk into the first room and pull enemies for us, whilst standing in the middle aggroing the rest and wiping us twice. After making it through the room and him clearly being the "first timer exp bonus" in the dungeon since he didn't eat any fruit to remove the debuff we kicked him (I think it's justified considering he didn't listen to anyone, didn't ask for any help and was just going to wipe us later again and again) and finished the run promptly with a new Nin which was a good ninja so I guess there are still good ones out there!