revert the ad nerf on twitch and give that nerf to vayne

Twitch needs a very slight buff, but he is not that bad where he is at. You have to remember, he can stealth; champs with stealth tend to do well if you can just properly use it. Also, it is hard to balance those types of champs. If I were to buff him, I would probably give him a bit more base armor, a little more HP/5, and probably a 2 to 5 AD base value buff. That would help with his weak early game (it might actually help too much and make him a bit overbearing; thus it would have to be tested to find a balanced area for increased numbers.

As for Vayne, personally I don't find her to be THHHHAAAAT OP. She is a bit strong, yeah, but the fact is that she is still a weak champ in lane and strong in the late game. If I were to do anything to her, I would probably remove some AS/lvl from her (not too much, but enough to make a slightly noticeable difference). Don't touch her base values, though, because her laning phase would suffer too much from doing that.

Right now she is "in meta", while Twitch isn't, thus she is doing very well. I guarentee once the meta shifts from late-game oriented team comps and more towards either assassin meta/early to mid game comps, she will go back to an only "okay" pick.