I disagree with the Bleach point. It was explained very clearly recently. Ichigo is (probably) the ultimate being in Bleach verse because his father is from a noble Shinigami family, his mother is a pure Quincy, and has hollow/arrancar powers passed down to him from his mother when she was attacked (as explained in the Fullbringers arc). He is the being Aizen wanted to become.
Kyouraku Shunsui said that the current training Ichigo is undergoing might make him too powerful to step into the human world because he may destroy it by just being there.
The reason Ichigo's bleading stopped against Kenpachi is because of his Quincy powers, specifically, Blut Vene. The reason he was pushed by Byakuya Kuchiki and Ulquiorra is because his Quincy part Zangetsu was restraining his Shinigami powers and when his hollow/Arrancar part took over he was able to unleash that power.