Doing this better than last time
Well I actually lost faith that so many people find the topic of whether or not Kai'sa is over sexualized or not is an important issue.
Let's ignore the fact that she needs:
-Less bonus AD scaling on her Q, as opposed to the flat 5% nerf. -W needs less scaling, it's basically a Jhin W but easier to avoid, it should be more rewarding to hit in terms of damage but not THAT rewarding. -E needs less movement speed %, asassins are supposed to abuse poor positioning however this champ can too easily avoid that mistake. Yes it takes time to charge up but not enough time, this can also be a potential area to look at.
Feel free to give your own thoughts on this, I'd find it pretty difficult to see anyone argue otherwise due to her winrate, ban rate and play rate all suggesting this is the case.