Getting into the big room where you enter the codes was the most painful / slow progress. As you have to kill the ones at the "back entrance" to have any chance entering the codes. This of course involving a lot of Lloyd's Beaconing back and forth. It would really just be painful to play as a solo knight at the later parts, even with two Gate Master peasants. But I wouldn't exclude playing as a solo Druid or Sorcerer.

I could certainly do Varn faster if I did it again. But I will probably forget about it by the next playthrough -- which is all good ^^

Now it's just getting the scroll of containment or whatever, and going to the Hive.

Cheers for your helpfulness