[Azimaith]

Well do you want original weapons or weapons from history?

Heres some fairly historical ones that aren't so commonly known.

Katars: Imagine sword stuck onto brass knuckles, thats basically what Katars are, they can get quite big actually. Just look it up on the internet, you should be able to get some good pics.

Baghk Nah (I think thats spelled correctly):
Means claws of the tiger, its basically a metal claw that fits on your hand, the rakes(fingers) coming out from under your fingers.

Yo-yo, well at leasts thats what we call it now.
It was actually an acient weapon that I believe orignated in the philipines, it consisted of a rock tied to a rope, thats right, just a rock on a rope. The ancient hunters would hide in trees and unlike their terribly inadequate previous weapons (big rocks) their new ones were big rocks with ROPES so they didn't have to climb all the way down to retrieve their rock.

If you want more commonly known historical western weapons I know tons of them, if you want an ability though, you would need to describe what your manga is about. You can't really expect us to think up a name, power, and weapon for you if you don't tell us who its going to be for, what time its going to be in, and what the general mood of your manga will be.