There are two things that I absolutely love about this illustration, the first one being the meticulousness and attention to all of the details that are present in it.
From the background building with the baffled man looking at the kunoichi, to all of those pieces of debris falling to the ground.
From the flower pattern on the girl's dress, to those kanjis on the sheaths of her swords.
The second reason is the dynamism overflowing from this piece of fantastic art: it's incredible what you managed to "catch" with a single illustration.
Oh, and the monochrome contrasting with the ninja girl's sea blue eyes is such a nice touch, I am so impressed by it all.
Most definitely keep it up! And once again, congrats!
