Vayne
Lets say Vayne has 70 AD, her enemy adc has 30 armor and 600 HP, both are level 2. Her aa will do 54 damage, her Q 70 and her W 44 true damage, thats over 220 dmg in less than 2 seconds.
Now, thats not much, but does Graves outdamage her with his 60 base damage and 0 early scaling Q, if he hits it? Or Corki/ Lucian with their 0 early scaling 80 base dmg Qs? Or Cait with her... 20 base dmg Q? All of them can be dodged with Vaynes Q too. Just wondering?

weak early game
Edit: Vayne might not be >better< than those champs early game, but considering the fact that shes pretty much the strongest late game champ in the game, she should be trash early.