User blog comment:Zulfiq/Post Dangai Training Ichigo VS Post Squad Zero Vacation Ichigo/@comment-1268838-20140917135947

In a certain way, I think that the two are essentially the one and the same. With the Dangai training, I think Zangetsu temporarily lifted most of his restraints on Ichigo's Shinigami powers, knowing that he would lose them anyway. By losing them, he would be kept safe, fulfilling his desire to protect him. I think this also makes sense, since Mugetsu is evidently the highest form of Zangetsu's power.

Only this time, Zangetsu let Ichigo go with his full blessing, hence why he now has his "true" Zanpakuto. With his Bankai, which we have yet to see, I think he will very likely be just as powerful as when he defeated Aizen, if not more so.