Ok - took your advice and grabbed to 1.9s maces and can get her to around 9.9m hp but at that point i'm overwhelmed with adds and it's over. I guess this is the right path, I just don't feel like I'm getting close enough.
Tried using unholy presence (faster strikes > more blood worms...?) and it was even worse, barely made 9m before soft enrage. I haven't been spamming VB, I'll try that.