Pardon me, but wasn't Kassadin missed in the assassin update?

Because it sure feels like it. You gave counterplay and delay to all the other assassins, making Kha Q multiple times instead of deleting you with one, making daggers a thing for Kata which can be dodged, giving Talon more to do than E+Q+W+R+auto or whatever his combo was. But Kassadin seems completely missed... you didn't touch him, at all. His damage is either targeted or undodgable AoE (if his E or R doesn't hit, it's either because you were out of range or he missed aka put his mouse in the wrong place, not because you dodged it, unless you flashed/blinked them but basically no one has blinks.)

I have no idea how to play against him, because if I try to peel him off well that only gives him another ability to kill me with, and if I don't, he's just gonna smack me with R's, autos, and Q's, and then he'll E me anyway because he charged it up himself. Fighting back only lets him kill be quicker. Baiting his engage barely matters because unless you kill him instantly, he can R away, like if Akali's R wasn't targeted.

Wasn't the whole assassin update about giving them delayed damage and with less targeted damage (less reliable damage)? In otherwords, giving them counterplay which isn't don't go near them? I can fight a Katarina, but against Kassadin, it's just a statcheck, and if he loses, well I either oneshot him or he R's away.