Well, Kai'sa's completely broken now.

In one patch, Kai'sa literally went from being bottom tier to top tier. She is absurdly broken right now, and until Riot nerfs her I'm perma-banning her from here on out. I would much rather deal with a Malzahar, Tryndamere, Tahm Kench, Gangplank, or just anything that isn't her. She does way too much damage, is really hard to pin down since she's super mobile, and her ult grants her a shield the size of the Eiffel Tower while also granting her the ability to gap close and reposition. Sure, Riot may have "hotfixed" her, but stripping her of 2 base AD and upping the mana cost of her Q by 10 can hardly be called a nerf. She needs to be toned way the fuck down before she can truly be considered balanced. If she's ahead, the game's over. If she's even, the game's over. If she's behind, she can catch back up and outscale everybody. With that said, the only way to truly beat a Kai'sa is to put her so far behind that she can't do anything, and then end the game before she gets strong enough to turn the game around, which is really hard to do considering that she can duel just about anyone. With all that said, ever since the release of patch 8.6 I haven't won a game against Kai'sa, nor have I lost a game when she's on my team. That is a sign from Jesus Christ himself, and he's saying, and I quote, "Nerf this bitch Riot."