User blog comment:Apocaylpse06/Ichigo Kurosaki's (New) Zanpakuto/@comment-1975828-20110815110510/@comment-28861328-20110817042930

Rukia did not awaken his powers. She transferred her powers to him. Am I saying the big sword he carried was Sode no Shirayuki? No. That is impossible, as a Zanpakuto is a part of their owner's soul. However, it was stated numerous times in the canon that the power Ichigo was using then, was indeed Rukia's, which is why Byakuya took it from him. It wasn't until after that, thanks to Urahara, that Ichigo learned he had his own Shinigami powers.