Yes, Fury is one of those blessing / curse swords, where it damages your various armor skills in exchange for some bonus straight to your attack. I found it, never used it.
What follows isn't much of a spoiler, but if you're as anal about it as I am, it might be.
It's one of those relatively rare Constant Effect items, too. I'm still looking for a soul that can give me that; the best (or most expensive, anyway) soul I've managed to get my hands on thus far has been a Hunger. I need to try to snatch one off of an Ascended Sleeper or something.
If you're reading this, don't tell me what souls give you Constant Effect; I want to find it out for myself. :)