User blog comment:Darksusanoo/Kassadin...his current state and possible rework ideas/@comment-5781707-20140920071547

The problem I've often heard about Kassadin is his obsene excess of movility:

Kassadin can't -in a balanced way- exist with such movility, and the same applies to Fizz and somewhat to Riven. These champions are easy to stomp very early (Riven con go eighter way), but theit snowballing is boderline unstopabble and even if they didn't do well laning phase they can almost always fed of teamfights and end up strong mid-late no matter what. The issue is that having such movility is possible and feasibly balanced for a champion, the problem comes when that champion has burst and significant crowd control in. Kassadin's slow is no joke (and please don't give him back a silence, silences on assasins are the worst possible thing) and Fizz ultimate is gross, and they can make you explote in a split second and get away without any problem. For comparison, Zed warping back to his shadows is predictable if you are keen, Katarina needs a target and a reset  and has to channel lotus, Ahri has to hit a tricky skillshot, Yasuo is predictable for his ult (at least on his own...) and his wall is more or less easy to bait, Kha'Zix depends on resets to get out and very very heavily on isolation, Diana might rip you face off in 0.8 seconds if she lands her Q but she ins't getting out easy.

Even if you push him into anti mage concept he won't really give a fuck late game as he can still show up on the Mark(wo)men and implote them like he does now. IMO The solution would be to gut most of his burst potencial and give him sustained damage instead (didn't his W used to do dat...?), yeah, his playstyle will be completly different, but his current is ouright toxic, and turning him into a fighter, as movile as he may be, he can't just make you go kabom while been as snowbally and unstopabble he is