User blog comment:Godisme/The Time Discipline/@comment-2120712-20110210043709

I think a piece of Shirosaki was left in Ichigo(very small piece) or perhaps its a fullbring ability of another to allow one to gain it. As they said the ability is pride in something that is symbolized in a an object, Chad is proud of his heritage which is symbolized by his dark skin, Ichigo is proud of being a Shinigami(when he was) which is symbolized by his substitute shinigami badge. We know the FTG gets rid of the powers but not permanently, after all Isshin got his after 20 years of human life, as I see it, its like with Quincy Final Form except the powers are sealed away. Fullbring will allow him to unlock it early. As I see use of FTG brought Ichigo back to dormant stage where his power is sealed making him human but won't awake for sometime so rather than wait like Isshin did for 20, for whatever reason, sense the power is there somewhere in his soul just sealed, Zcution is gonna bring them back early through the Fullbring method, remember we know Ichigo had hollow powers at one time.