This is just a build I idea I was playing around with in AB/Isle of the nameless today.
I was thinking that if you could get a dual attack off with IW in then you would hit for 2x40 damage (80) but then I realised that the lead an offhand would have to hit to be able to do this, so it wasn't possible. That was until i saw these two skills. [Dancing Daggers][Exhausting Assault] This means I can do damage with Dancing daggers and then go straight on to Exhausting to do a duel attack.
The Build I ran was something like this: