Vayne E SHOULD NOT apply her W PASSIVE, do 0 damage, and cost MORE mana
That's how you balance vayne.
currently she can free harrass you not even doing 3 auto attacks, she can just do 2 auto+E for 3 stacks of passive, she has no mana management whatsoever, infact 1 of her spell is a passive that cost no mana, and the E cost not that much and it's situational.
Vayne should be ONLY based off her positioning and autoattack, so why is this thing even allowed. E shouldnt even do damage, should just knockback and stun into wall and thats it, and cost mroe mana so that you can use it whenever you feel like it