You know the best mechanic to fight them? Kite around and damage, keep doing it, potion up, kill minions it summons for potion charges, kill it off. I did a lot of them in the first few hours, getting some orange pieces stashed for use. I also played about 18ish hours this time around, plenty of breaks and nourishment. :)

I am keen to check out end game stuff on standard non HC though, later in the week after a few days break haha!

You got plans on any specific characters?