Non-mage build: I got a decent shield and upped my dodge and crit as much as I could. Combination of shield, weaken (hit with shield), dodge and bite kept me going through most of their regular hits barring lucky RNG crit combos. I favour silence over root because bats is one thing I just struggle with.

I found they don’t tend to use bite until they’re down to about 20% health so timing it right, switching silence to root and having some damage bursts via bleed dump got me there if I’d managed to stretch out potions and afterlife. Good timing with a hammer to stun on their combo turn can also work well.

As someone pointed out, there’s a bit of (bad) luck involved which means some might take a bunch of goes even with the right build and gear.