Level: from 20
time available: 3 h
you need: Fatigue 0 and Grp 1er
Normally, it should not be too much of a problem on its own.
In order for the final boss to appear in the last cave, you have to kill the 3 other bosses beforehand. You should have finished all the quests in one run.
Pay attention to the map and always turn right, then no boss can escape you.
If you are in a group, you should not leave it, otherwise you will fly out of the cave. You should also not join a group if you are already in the instance, otherwise you will also fly out of the cave.