Awwww it's Byakuya!!! <3 This is an awesome drawing
I really like this drawing of Byakuya. It is neat and gives a strong battle emotion to those who see it. >.< Somethings that improve this drawing is to change the shade of colors a little bit. For example, Byakuya and his shinigami robe's color is black with pinkish shade. I do admit that pink suit suits Byakuya, but the pink is a little too strong. This makes the picture appear blurry or unclear at first sight. Believe me, first sight is very important! ^.^ Maybe a little less shade of pink on the robe and hair would be great.
Another thing I would like to critique on is the outline of the artwork. outlining of a work must be neat and done with a well choosen color. The outline of a drawing is what make a viewer catch their eye on the artwork. The outline of the 'Bleach' logo sign should be traced with a slight stronger pink in and around and the lettlers the make the sign stand out. Byakuya should be traced with a really dark grey that is lighter than black.
In general, I think you did a great job of techique and skill. This is just a little tip that I think you could use to make the drawing look better :3