As most of us know by now as a vampire necromage can enhance all kinds of effects we use on ourselves, but I found it has a significant effect on dual flurry. Taking two ranks in dual flurry multiples the weapon speed by 1.35. Necromage seems to be increasing the whole thing by 25% not just the .35. Now to those rushing out to try this themselves necromage is not retroactive. If you aren't a vampire with necromage before taking dual flurry it won't work.

Additionally the effects remain after your cured of vampirism. This is because the fortify effect is applied when dual flurry is taken.

That's certainly good to know. Thanks for posting!