Ok as revealed in chapter 541 the blade and me 2, we learned Ichigo's strength has been held back by Old man zangetsu. We also learned that Old man represents his quincy powers and has been pretending to be his zanpakto in the form of Juhabach from 1000 years ago.
So all of Ichigo's powers we've seen so far were what Old man couldn't suppress.Now one thing I think people are over looking is maybe this explains why Ichigo cant control his spirit energy. The more important point is in my opinion is ichigos hollow powers have been held back. So the form during the vizard training, his hollow masks, and lastly the form who fought Ulquiorra could have been held back as well as his shinigami powers.
To me this is very interesting does zangetsu have other powers?, was he holding back some of ichigos spirit energy, if so how much? Did ichigos hollow powers get restrained as well? Could he have used his mask for longer? and so many more. I cant wait to see how these new powers will work. Cant wait for 542