Kai'sa Problems
I have some very serious concerns/issues with Kai'sa beyond gameplay from what has been shown so far.
For starters her design, for what she is described to be she looks nothing of the sort, almost deviant-art levels of fantasy, supposed to be a person who grew up and adapted inside the horrors of the void, forced to bond with a void creature in order to survive, fighting every moment just to stay alive. However, if you take this descriptor and then look at her splash art, she just looks like "Sexy Female 33 with shoulder cannons" now I don't necessarily have an issue with her being attractive, what I do have an issue with is that it doesn't make sense thematically. If she is supposed to be someone who is desperately trying to live and fight for survival in the void then why does she have perfect skin and makeup on with exposed cleavage, there should at least be some indication that she's been struggling to survive, on top of this, her voice lines also do not reflect her thematic at all either, I understood the "dead pan" attitude she has since she's been away from humanity for so long, if more lines were like her first movement ones she would work much better thematicaly. At this point should just retcon and change her lore before even releasing it because it doesn't work very well together for what her story is trying to convey (from what's been seen at the moment that is).
Second off, gameplay, from what I've seen so far through PBE (not even mentioning theme/appearance of the abilities) is that she kind of feels like an incomplete champion, or well a not very well fleshed out one. Every champion who has been related to the void so far has had an entirely unique kit despite being from the same dimension and thematic, Vel'koz and Cho'gath both have distinguished kits despite being from the same thematic, the reason I mention this is because Kai'sa's kit is entirely composed of re-used or very similar abilities to the void champs and more.
P = Kha'zix evolve + Vayne silver bolts Q= Unique W= Vel'koz Q (I swear its the same animation from the star guardian vel'koz) E= Xayah W + Vayne invis (when evolved) R= Long range Akali ult with shield
My problem doesn't come from the fact that they're "reused" abilities, but it stems from their unoriginal use of them in Kai'sa's kit, abilities have been recycled before but they've always been different takes on what they can do, (Swain E vs. Ahri Q vs. Ekko Q vs, Gnar Q, all similar premise, skill shot that goes forward and then comes back, but all function differently and are used differently). However, in Kai'sa's case the abilities she has in her kit that are "recycled" function in the same exact way as the originals, leading to her feeling not so great to play since her abilities don't synergize very well with each other for her functionality and don't seem very "new/original" either (on top of that her ultimate is the antithesis of what an ADC/Marksmen want late game unless really ahead).
I'm not trying to hate/flame this new champion but in terms of quality and design it is definitely a step backwards.