Hello and welcome, for this build of vayne will allow you to have a extreme amount of damage early game. this will allow you too harsh much more.

For the runes i have gone for complete attack damage and some armor, or you can go magic resit, up to you. This help your tumble extremely well giving around 250 damage per tumble.

For items, open up with a Dorans Blade. This gives you 3% life steal which can help during early game. You would not want to go back until you have enough for your boots, i recommend after reaching level 6. After getting boots, you want to aim for your BF Sword and Bloodthister. The damage increase will help your tumble very well and lifesteal is very much needed. A Blackcleaver does almost the same thing as a bloodthrister but help with your attack speed. many people would go with phanton before but we want to improve our tumble not our sliver bolts. Now we would want our Phaton. At this point we should be doing around 400 damage from tumble alone. Our phanton will help qwith movement speed and attack speed giving our sliver bolts easier to land. After this we want our Infinity's, This purely for the AD, making our tumble around 600 damage. After this we want to build either health,armor or magic resist depending on the other team. This is up to you to decide but i have given some ideas appove.

For the skill sequence you want to max out tumble as fast as possible for max damage-out put with this. After maxing tumble, sliver bolts is your next option and than condem. this will allow a lot of damage thoughtout the game.