Here is what I thin about assassins/kind of assassins:
Zed - very well designed and fair to play against in teamfights, kind of oppressive early game, was in a perfect place and didnt need any tweeks
Talon - was kind of boring, used to get free trades with silence, after that being removed was kind of shitty but could have been fairly countered with pink wards, now he seems ok and fun, but feels like he is missing something to make him just a bit stronger
Katarina - was easy, unfun to play against and had really low counterplay if you were a squishy before the rework, yes 1 stun fucked her but her combo would kill a squishy in 1 second if fed even a little bit, and I am saying that as someone who played Kata very very much, especially season 6, now she feels perfect and I dare say that her rework is by far the best out of the assassin reworks
LeBlanc - her combo was stupid and unfun to play against, especially when she had silence in her kit, now she feels ok, she didnt need this new extreme waveclear and it fairly got removed, also the chains are way too long now, they should halve the range and compensate somewhere else
Ahri - still not nerfed for god knows what reason, can kill you by spamming R and W around you while missing her actual skillshots, so she needs some nerfs (which she wont get because of hentai watching fapping nerd army defending her)
Fizz - god will they ever fix this champion, the worst thing is that he was kind of balanced before the update, but now he has an impossible to miss shark so it feels even more retarded to play against him, at least the tank build seems to be dead, he has a problem that his "identity" is his toxic E which makes him very hard to balance
Ekko - is stupid because most of his AP damage is on his E which is his "noob skill" , also the fucking tank build that lasted 6 months and ,unlike fizz, still fucking works, he needs a rework because he is too overloaded for him to need to go glass cannon
Diana - should not really be an assassin, but usually is when snowballing, she can 1 shot multiple targets in second, she needs some rework to be more tanky, more dps and less burst
Akali - probably the most toxic AP assassin because she requires the least amount of brain usage to play, if any, can snowball retardedly hard, but has 0 utility to help if she didnt snowball, making her a terrible design, needs VGU asap
Rengar - wish they deleted this champion who has been a problem since his release but unlike some champs that they ignore (Lee Sin) they actually tried to fix Rengar multiple times and failed miserably every fucking time, they NEED to drop his theme, drop the fucking ulti concept, drop the bonetooth bullshit and make a new champ that wont feel frustrating af to play against
KhaZix - here is what Rengo should have been, also posed a problem multiple times but ultimately he is very well designed and was balanced untill the update gave him needless power boost, but after the recent meta shift he is ok again, still I feel like they should have left him as he was, now there is even less decision about what to evolve first, if you dont do Q-E-R-W you are an idiot honestly
Shaco - was always annoying, but never had any problem with him, update was pretty dumb and pushed him to high win rate, now he is gutted so I really dont understand what the fuck is riot doing with this on