User blog comment:Willbachbakal/(Champion Rework) Kassadin, the Void Walker/@comment-25228021-20150301123536/@comment-1330314-20150301141731

Seven seconds of unrestricted, enhanced movement and untargetability is anything but weak, and in several cases would even be a buff to Kassadin (he'd be able to go over much thicker terrain). Compared to, one of the most powerful steroids in the game, it's an even stronger movement speed boost, for example. I also specified Kass phases out of Riftwalk if he attacks.