not a fan of kassadin having a silence again. him popping over a wall and silencing you is what made him traditionally such a a pain to deal with, the magic shield feels more fair because you can still lock him down with CC if you have any or use your escapes if you have one, and if your AD you can just ignore it and fight back, despite these drawbacks it actually improves his teamfighting by lowering the chance hell get popped for jumping in. it serves to balance out his natural strength of hunt you down for 1v1 kills, and his teamfighting potential.
kass might need buffs but the changes he could use are easy to spot from the laundry list of possible minor buffs. obviously riot should not do all of these things at once, please buff responsibly.
+50 range on R (500 from 450)
change the shield from a magic damage shield to a regular shield (better lane matchups, possibly better teamfight survival, realy like this one as AD assassins are a common counterpick, and lane swaps are brutal if he goes top)
buff his W (the risk of going in and auto attacking or even more risky a auto + reset auto means power here has risk.)
plop a small bonus back onto his passive again (it used to give AS which was essentially worthless to him, double passive!)
control warrior and handlock seem like they fit the bill. control warrior usually holds card advantage and is a pretty straight forward play and of course control is in the name really. handlock has tons of possibilities because the whole point is holding a gajillion cards at all times.
i would suggest miracle rogue but they are pretty fancy pants combo heavy, also apparently mircale isnt as good as it used to be cause of card nerfs to leeroy, gadgetzan auctioneer, and defias ringleader.
of course i picked up HS like 2 weeks ago so I only have the bear minimum knowledge on this subject.