About the artist:
Her is an original character designed by nil and was used here.
I don't know this one's source since I just got it from other image board and didn't see it on any redjuice or nil related sites, the style is more like redjuice IMO though. Furthermore, I found this page which have two rough/sketch images (one with signature, I can't recoginize anything except "2011" :P) of this art and the uploader said it's by redjuice, so I just followed.
If anyone is sure about the artist, just change it and leave a message here (it would be appreciated if providing the source). Or nil & redjuice are just same person? :/

i could go for some katanas like that ( my fetish for swords is so big i didn't notice the girl till i looked dow them and it took a while ) but i love the whole picture

redjuice did not draw this

NIL has draw another works about this character

Ok, I found source now.

I remember that nil has a course of painting using the same character as this pic

terminator1990 said:
I remember that nil has a course of painting using the same character as this pic

I've mentioned it..

fireattack said:
here

http://twitpic.com/photos/niru_NIL
this is the nil's twitpic.
in that page, yon can find this pic.