Before i start this yes i just played against a katarina player that was also a good player and yes she killed me plenty, but we still won the game.
My problem with katarina is that simply put she has too much damage for too little risk and yet she struggles in lategame teamfight situations.
So she's too strong at assassinating people, on my main vel'koz you may aswell just put your keyboard down if kata for some reason finds you away from your team as there is literally zero counterplay to her at all, she will jump on your face and will kill you even if you have banshees veil, flash, protobelt and barrier. If you ask me she is just a toxic champ that needs to get changed. The only problem with kata is she does too much damage, not the fact she has a trillion dashes or has the safest laning phase in history or has no mana to worry about. She straight up does too much damage and can go in on you without any fear.
As vel'koz you know what the only strategy is vs kata in lane to avoid dying? farm with q at a distance, don't bother lasering basically ever, don't throw any skillshots just q minions from afar.
What fun league of legends is. e.g nerf kata make it actually possible to duel her if you play well even as a champ like vel'koz that kata is supposed to counter.
Other assassins? Banshees veil actually works on fizz as it prevents his ultimate making his life a million times harder and of course zhonias for zed, akali can't do much til at least level 6.
Kata? can kill you at level 3 if you come too close to her. I don't want to hear "don't stand on her daggers" all she has to do is walk up to you throw her dagger which requires zero aiming and then jump on you, you have no choice but to stand on the damn daggers.
No item works on katarina she has low cooldowns and can break veil easily and doesn't rely on her ultimate to kill most of the time anyways, zhonias? she will cancel her ult and then kill you with standard abilities, you can't run, you can't fight.
She is a toxic disgusting champion like evelyn and needs a rework to buff her teamfighting potential while nerfing her overly strong assasination game for bronze keyboard mashing scrubs.