How does Abyssal Palace sound to you? Have you been in that place before?

Well, Abyssal Palace is some sort of Dragon cave. You have to kill some monster too in order to some certain rewards...

In order to do this QUEST you have to do the following. Be prepared at all times. You must be level 90 and up to this Quest.

Talk to Busuk, ask him to send you in the Abyssal Palace with your own time to save their Prince...

I've said that it looks like a Quest of a Dragon Cave but it doesn't require getting you some stones. All you have to do is to kill all the monsters to open a gate.