By Pandemonium.Ironguy 2010-05-30 00:05:58
I guarantee you it's that, and rest assured that's the thing that annoys the living *** out of me when it comes to fighting certain Monk-type monsters (Silver Sea Remnants floor two, primarily since they'll screw Penta Thrust over big time).
If you want solid proof of it though, give NE Apollyon's first floor a shot. The one with the goobbue boss, as well as the black and white mandragora everywhere, to be exact.
The mandragora guard nearly every third weapon skill you'll throw out, it's very disgusting; just need to use a single-hit weapon skill, and you'll see for yourself easily enough I'm sure.
All that aside though, I'm 99.5% sure that Zanshin cannot process on a weapon skill (as much as no proof to prove it seems faulty).