Hellou, I don´t know how many know this, but if you kill this "Dark Sky Ghost" mob near the Wuan Village, Zhengzhou (White Side). It will give you a quest (I don´t remember the name). Where you can talk to one Soldier Dude. The quest updates and when you play it through you will receive 2X Inner Medicine of Mythical Creature EXP boost. I don´t know the spawn rate, but I think it's some hours maybe.. I hope it helps you in some way! ^^
Give the quest name and the NOP from who you get it, I have killed lot of this but didn't see the quest - only items filling my inventory
