Gain increasing amounts of AD or AP, Adaptive over the course of the game.
WhyPress the Attack
The auto-attack reset from [Q] allows you to quickly proc Press the Attack, especially in extended fights where you can repeatedly deal damage.
Overheal is a good option here if you think you're going to struggle a bit in the laning phase and your support is able to provide heals either as a Melee with Targon's or a healing champion.
Triumph here is mainly to keep you healthy after a kill and play up the reset nature of your [R].
Vayne is all about getting as many auto attack off as possible to proc [W]. Alactrity's bonus Attack Speed also empowers you ability to proc more instances of Fleet Footwork for more healing and chase.
Cut Down is the most reliable form of damage amp for an AD Carry, largely thanks to the fact that you do not build any health items.
Absolute Focus' additional Attack Damage is great for back-line carries who can keep their health high with good kiting for additional damage output and carry potential.
Vayne is all about late game scaling and there is no better scaling rune than Gathering Storm. If you can make it 30min+ game you will be an unstoppable force in teamfights.