I honestly don't know if Vayne herself is the core problem with her balance at the moment

She has a pretty polarizing design, I don't think anyone questions that. But vayne is a champion who is supposed to be a late game terror and especially good against beefy targets, naturally with bruisers being dominant and even tanks still being good, that much makes sense. But at its core, why exactly is Vayne doing as well as she is when just 5-6 patches ago, she wasn't considered very good. What's changed?

I know her Q was buffed in 5.14 to have the CD begin upon launch of the attack as opposed to it hitting. That's more of a teamfight buff, which is debatable whether she needed it or not. Regardless, it doesn't suddenly make what's supposed to be her weak point, lane phase, any better. I know that ADCs have been nerfed and by default that raises her level of power but I'm still skeptical at best that these two things alone are the reasons shes gone from hardly being played to the best ADC by far in just two short patches.

I suspect two things could be at fault here, neither of which is something that should be addressed directly either.

Vayne is one of the view ADCs that rushes botrk, giving her a pretty decent chunk of sustain that often times the opposing ADC isn't going to have. This leaves you with effectively two options: try to poke her out or all-in her. The problem with option 1 is something I'll get to next but for now I'm gojng to cover option 2: vayne is really not an ADC you can all-in during lane phase, especially post 6. You're going to lose that every time because of final hour because holy shit, 30 AD at level 6 is massive. Not to mention the stealth, where in all probability you won't have a pink Ward for her at level 6 or so after. I think if Vayne does end up getting nerfed, this is where Riot needs to focus. Access to this kind of power on a champion that is supposed to be weak early and start to slowly scale into mid game is pretty crazy.

But before I go further, let me go into option 1 I mentioned above.

Option two is that poke supports are actually kind of bad at the moment. The best supports, in no particular order, are Alistar, Braum, Thresh and Janna. These are supports that are all good with Vayne, especially Janna because she makes Vaynes relatively weak 1-5 much safer. Alistar and Braum are extremely good at all-ins and Vayne is probably one of the best carries when it comes to going all-in, especially post 6. This likely isn't a coincidence. And in that same token, even though she is prone to chain CC and dying like any other carry, despite these all-in esque supports being good for her, they're hardly good against her.

Let me put it like this: imagine of Zyra, Sona, Etc were good? What could a Vayne do against that? She's outranged or completely incapable of matching the poke these champions are capable of dishing out pre 6, and they're not exactly supports you can all-in post 6 (lol just dive ZYRA). These are two examples of poke supports but I suspect this is part of the issue too because I've watched Vayne against Vel'Koz support about 50 different times now and Vayne has been absolutely crushed in lane because she has no answer to deal with that. So when she's good with all-in supports and good against them, it is a contributing factor. How much so? I'm not real sure.

I honestly believe Vayne being what she is late game is fine, much to my dismay and personal bias. But when Vayne is not having difficulties early, there is a problem. I don't think ADCs suddenly got too weak, I think that's more because of the support issue I touched on. But either way you put it, facing Vayne post 6 keeps you on pins and needles because you know if she has a heavy CC support, you can go from 100-0 at any moment. I think if you directly nerf her as opposed to letting this play out and see if the meta changes itself, reducing the bonus AD on final hour to something along the lines of 20-25 at rank 1 is a good start. Others have suggested removing her base damage on W but I think that would completely make her unviable because of how it would ruin her entirely until basically W has 3-4 points in it.

But yeah, I don't know. This is kind of what I suspect. Idk how much it is true.