Board Thread:Questions and Answers/@comment-4982581-20130209214649/@comment-5809213-20130216025940

Well, in that chapter, a man who's wearing a white hakama can be seen on the back yelling: "Bastard Kurosaki!!!". Plus if you can take a closer look, you can also see that the man has a very remarkable scar that goes from the stomach and up. In my opinion, these 2 facts heavily hint that "mystery man" was none other than Grimmjow Jaegerjaquez. Other thing to take on account is that whoever appeared at the exact moment where Ichigo lost contact with Urahara, was wielding a Katana. If you analize carefully, of all the surviving arrancars [the confirmed ones of course] only Grimmjow has a Katana-like Zanpakuto. Neliel doesn't count since she was left behind and she cannot transform by herself into her true form. Also, the "mystery man"'s katana's description closely ressembles that of Grimmjow's Zanpakuto.