User blog comment:Seieireppa/God Eater:Universitas, chapter 47: Wings Towards Tomorrow (Arc 2 final chapter)/@comment-1419424-20150729023551

Also, in case anyone's wondering about the similarity of Blake and Jack's powers to those of Ken, allow me to provide this handy diagram:



The big arrows represent the flow of time.

In Ken's case, he merely jumps back to an earlier point in time. In the case of Blake and Jack, however, time itself is rewound.