Assassins that continue to be a problem post update.
<- My boo but I will be honest with myself
All these champions have some major flaws in their design, but different types of flaws.

She is the definition of blow your enemy up without them even having a chance to react. Her Etheral Chains has one of the longest tether ranges in the game, making it impossible to escape unless you are
and have flash. Her burst damage is still way too high and she doesn't even need a full combo to kill someone, and her mobility is still too great for achieving all of the other stuff I just mentioned. Kind of like pre rework Kassadin

He has a similar problem to Leblanc, is that he will hop out of the shadow and just obliterate your ADC before he or your allies knew what the hell just happened. All of his damage is focusing in to one ability, which makes him particularly easy to master, and on top of his damage being mostly focused into one ability, it's pretty easily chain able, meaning you can easily get 3 Q's off in a short window if you know what you're doing.

Sure she has a bit of mechanic now, but she is still just as snowbally and bursty (if not more) than she was before. Moving her W damage and effect to passive was the wrong way to go, because now you've just gone and made her even MORE spammy. Her Passive ratio is 287 base with a 1:1 AP ratio late game and also has a 125% Bonus AD ratio, meaning that if a Kat is smart she will hop on you from her Q's dagger, immediately throw down her W and ult in rapid succession, and you can say bye bye to your health bar. Let's not forget they ALSO went and increased her ultimate damage. And let's not forget that each dagger she picks up literally resets the cooldown on her Shunpo, addind to how much she can spam abilities.

He's the type of champion that you see and are like, Oh shit I'm dead. This should NEVER be the case in league. This guy literally throws out his R, and almost always hits it because of that stupid auto attach mechanic on his ultimate, that by the way, another champion they increased the damage on his ultimate, will proceed to murder you in two ways. Either you take a max range ultimate to the face and he proceeds to Q you afterwards for the kill, or you walk closer, take smaller ult damage, but then He Q's you then double auto's you with the reset on his W. He is the definition of infuriating to play against.

Akali is the definition of feast or famine. She either snowballs really hard, or falls behind very hard and is hard to come back on, unless your team is bad enough to let her come back. She lacks a clear identity in her kit. They want to preserve her sustain, they want to preserve her invisibility, and they want to preserve her dashes, which makes her EXTREMELY hard to do anything with balance wise. IMO her Shadow Dance has always been her iconic ability in my eyes. Never her sustain or invisibility. Well maybe a bit of her sustain since she has no real defensive stats. She just needs a rework at this point that revolves around her Shadow Dance. Not 3 abilities and completely make or break her.
Thank you, that is all, let me know what you think, and please don't down-vote without a reason.