Hello,
I've created a not so good version of the Fruit Ninja blade at someone's request on the forums. You can see a video of it here:
Sorry it's a little choppy and the particles look much better when not choppy. But anyways… My meathod in this prject which you can find here was to set off particles in the opposite direction of my mouse at random speeds. It didn't work too well. But if you want a little more realistic version, here's how I would do the particles:
The way you would put the lower set of particles there is by setting the offset. I think someday I will attempt this meathod, but for now, I'll leave it up to you. I hope that helps!
Thanks!