I found that one frustrating as well, which is why I always stick to this same tactic over and over again whenever I reach that place:
I make sure my character is overpowered.
I attack whatever is on my sight. If they're close to Zandalor, I attack them. If they're far from Zandalor, I'll attack them too. I just attack, attack, attack.
I remember in an instance, Zandalor had to keep restarting his magic portal thing because I couldn't draw enough enemies with me. I had a melee character back then, and all I did was not give up and just mindlessly hack all over the place.
And as luck would have it, it worked.
Sometimes all it takes is a little bit of luck and a little bit of common-sense strategy.
