Well just kill laiken again and get through with first dragon battle, as still its quite easy in high difficulty mode. The mobs only manage to drop around 200 of my dragon hp before I clear them all out.

As for those skeletons in the cave behind waterfall, it wont pose much problem if you character is well gear, even if you are just only level 20. If you are poorly geared, even with higher level also, the mobs still can pawn you easily.