No clue on that book as I took the other necromancer.
Glad you got dual weapons working though.
For that Barnabus fight I had my necromancer creature and my level 1 or 2 demon.
They held Barnabus in place and distracted him while I dealt with his summoned demon then he was easy work. My creatures were distracting him and I just held back and stuck arrows in his butt.