I think the hardest part is ahead. I remember the 3rd quest (Ick Swamp with a monk, no prep) after the monk nerf. That was
nightmarish. You're either poisoned or mana burned right from the start (both if unlucky) with a touch of corrosion because the map is filled with plants you have to kill to progress.
There's vampires & warlocks for magic damage, nagas that weaken (and the boss is a naga with 380 health and 50% resist).
The good part is that there's meat men, wraith & gorgons to power level, and after completing that quest, vicious dungeons won't feel that hard.