HOW TO FIX VAYNE KIT
Vayne has always been a champion players hated because of her low counterplay kit (mainly because her percentage max health true damage w).
Now look at Fiora. While she might not be perfectly balanced, she adds counterplay to her kit because the enemy player can position himself to not get hit by her passive true damage.
My idea would be to make Vayne position herself to apply her stacks (instead of procking them like Fiora).
Let me know your thoughts! <3