I can't whack this guy! I need to get by him so I can get to Luskan. How does one do it?

Buff up before you enter the area. Any spells that gives you a bonus to AC, damage resistance/reduction as well as any bonus to AB is useful. Potions of Barkskin, Bless, Aid, Bulls Strength etc., will help if you're not a spellcaster.

You might want to try mind-affecting spells or death spells on DB, but I can't guarantee an effect.

Yeah, I ran into him last night. I even had Grimgnaw with me and we still almost bought the farm. Very tough fight.

He comes unexpected, yes. Probably the only time in the game where I was taken by surprise.

Exactly, Stratos! I really liked the fact that I was totally surprised. I wish more of this would happen in NWN, though I am still enjoying the game a great deal.