Why Vayne's mana costs are ridiculously low?
We are talking about a champion that has no cost on his W since is passive, and the other spells she has are really low on cost. In general you'll never ever see a Vayne go out of mana, or a vayne that has to limit herself in lane to manage her mana.
Then why have a mana bar? What is the point of that, and don't tell me that Vayne has a weak laning phase because honestly that is BS.
She should really have her mana costs adjusted so that she cant thumble infinetly, but has tio think a second before doing it. Also the fact that her E is very situational and not something you will use frequently and the fact that her W has no cost really contribute to this thing.
She needs some balance in that sense