User blog comment:Xilinoc/Ch. 540 - The Sword Five/@comment-1043846-20130607042928/@comment-1043846-20130608045736

It can be that since his mother was a Quincy, and mothers are obviously far more important in a child's life plus the trauma he experienced from his death, it all may have suppressed his Shinigami powers and, for a time, Zangetsu could freely mislead Ichigo and his Hollow coming to power was to be his Shinigami rebirth.