Yup… my loathing for this hero knows no bounds.
I found the effective way to combat her… carry a secondary load of small mana potions with a dispeller (Sonya, Caedmon, etc). Keep the dispeller charged in readiness. When she fires her spell, you top up your dispeller with a small flask and then hit her to remove her heals.
It’s expensive in mana flasks (and not even so expensive if your team grants you the luxury of using a 2nd battle items slot for small manas) but it works.
For the final battle in Intermediate, I just blew all of my direct damage items to lower her health some, and concentrated on taking her out first. (I had Boril which did a good job of lowering Author’s health by reflecting his attacks). I then spent some mana potions on strategy above to take her out. Once she was gone, the battle became more manageable… although taking out the other vampire wench was still not fun, but doable once you’ve opened some slots to charge up your mana without giving her any).
I really DID NOT enjoy that battle, nor the event as a whole. Not going to bother with Advanced… especially not for the rubbish loot. (Don’t need the Sturdy shield and got plenty of what else is on offer. Waste of time.).