This is mainly because my build gives vayne a much easier time kiting your opponent and putting out more autos to proc your w faster.And since vayne is squishy my masteries and runes help to give vayne at least 594 hp and 66 ad with the long sword and 0.83 attack speed at level 1. And since vayne has no sustain early on, you have three pots to last the laning phase giving you a super advantage over your opponent adc. I am not a good adc but i know that my build works, if used by a good adc, this build will show its full potential.
Cheers to all you vayne adcs out there.

3%LifeSteal from the dorans blade and the Perseverance mastery , firstly if you use the standard vayne runes/masteries you would have 73 ad. If you use my build , you should have 66 ad with my long sword. 3% Lifesteal of 73 ad is 2.19 hp per shot regen.

Now my build , Perseverance and recovery makes me regen 4 hp per second ,i would regen 20 hp per 5 seconds.

Practical data, if you were to have 3% life steal and you auto twice per 5 seconds, you would regen 4.38 hp per 5 seconds , perseverance and recovery would still easily over heal 3% life steal from dorans blade.As i regen 10 hp per 5 seconds. And when I'm below 20% hp i would regen up to 21 hp per 5 seconds. which is insane for survival.

-Cons
-High skill-capped
-One wrong tumble might kill you!
-Condemn may save your opponent if used wrongly


-Pros
-This build gives you a super strong laning phase
-Enough attack speed to kite your opponent really well
-3 pots and long sword for tremendous sustain in lane plus the perseverance mastery
-The long sword also helps to cover up for the lack of ad . With the long sword you would have 65 ad at level 1 which is more than enough for any adc at level 1.
-The attack speed from this build helps players to farm better even with the slight lack of ad.(Fervor of Battle makes up for it! )

If an adc uses the standard vayne runes/masteries and buys dorans blade. He would have 595+hp but he would have one hp pot!

If an adc uses my build , he would have 594+ hp and still have 3 health pots to back himself up in the lane if he were to lose to trade against his lane opponent and easily stay in the lane way longer than his opponent while still being able to farm safely due to my masteries and runes.

This masteries and runes that i personally designed myself specifically for vayne, gives vayne 28 armour , 594 hp , 66 ad , 0.83 attack speed and 38 magic resist at level 1 with 3 hp pots!

The standard vayne runes/masteries gives vayne 28 armour , 595hp ,73 ad ,0.77 attack speed and 43 magic resist at level 1 with only one hp pot ....

0.83 attack speed and 0.77 attack speed , no difference?
Think again. 0.06 attack speed is a huge difference in the landing phase, test it you won't regret it.

Now fervor of battle increases 1-8 physical damage depending on your champions level per stack.This stack can be obtained by simply auto-attacking anything. The stacks will not go off unless you stop auto-attacking for 5 seconds.Which means its buff is almost always there.Lets be realistic who is an adc that does not auto at least once every 5 seconds in battle/lane.
So at level 1,at 10 stacks you gain 13.2 additional physical damage to your opponent on your auto-attacks including tumble for your information.
At level 18, 10 stacks give you 80 additional physical damage to your opponent on your next auto-attacks.(INCLUDING TUMBLE) This is an item by itself!
Now warlords bloodlust, in calculation, as an adc, if you crit doing 200 damage , you heal for 30 hp. At 1000 damage you would heal for 150 hp. Its good if you rely on crit to help heal you. But this honestly is preference.

In conclusion,for vayne fervor of battle is good early-mid game and even late game.
But warlords bloodlust is applicable to late game crit damage.If your willing to place the bet that they won't get tanky to counter your crits that is. Remember 15% of your critical damage(2 second cooldown)

In this 2 second cooldown, fervor would have at least done an extra 160 damage at level 18.

I honestly think that vayne is better with fervor of battle. Since she builds botrk first.
So warlords of bloodlust is only useful later on.

I built infinity edge after botrk is because i would have enough attack speed for mid game already due to my runes/masteries.
Followed by a phantom dancer which is just a must have for most vayne builds.
I then get Lord Dominik's Regards for more armour pen and damage from the hp passive.
My last item is bloodthirster because i just love some extra sustain but you can replace this with mercurial scimitar or a GA. Its preference, but of course if they build thornmail get BT.

Its very important to note that even with my runes/masteries. You still can't go ham at level 1.
At level 2,when you have your silver bolts you can trade with almost anyone due to your attack speed.
This build helps adc with farming as most vaynes including me have problems last hitting under tower/pressure.
The long sword and 3 pots plus my runes/masteries keeps the pressure off as you will have solid sustain/tankiness in lane. And still able to destroy your opponent with your attack speed.

As vayne, it really is key to stay behind your team and close to your support.I really cannot emphasise this enough. As vayne, being caught out means death!
Many including myself have always dreamed of making plays and always forget the importance of positioning and decision making.

When entering team fights, its best if you have both summoner spells up.But thats rarely the case.
Regardless as vayne or any adc out there, you must know when your opponent spells are up, always keep in mind if they have a crucial cc . Predict it and dodge it. If not at least put yourself in a proper position to minimise the damage done to you as much as possible.

And it normally means staying with your SUPPORT!(NEVZAT&MERT)

Vayne's Passive:
Vayne ruthlessly hunts evil-doers. She gains 30 Movement Speed when moving towards an enemy champion.

Vayne's Tumble/Q:
Vayne tumbles, maneuvering to carefully place her next shot. She rolls toward the cursor and her next attack deals 30/35/40/45/50% bonus damage.

Vayne's Silver Bolts/W
Vayne tips her bolts with a rare metal, toxic to evil things. The third consecutive attack or ability against the same target will deal 6 / 7.5 / 9 / 10.5 / 12% of the target's maximum Health as bonus true damage (Max damage vs. monsters is capped at 200).

Silver Bolts' damage bonus cannot fall below 40 / 60 / 80 / 100 / 120.

Vayne's Condemn/E:
Vayne draws a heavy crossbow from her back, and fires a huge bolt at her target, dealing 45/80/115/150/185 (+0.5 per bonus attack damage) physical damage and knocking them back (900 units). If they collide with terrain, they are impaled, dealing 45/80/115/150/185 (+0.5 per bonus attack damage) bonus damage and stunning them for 1.5 seconds.

Vayne's Final hour/R:
Readying herself for an epic confrontation, Vayne gains 30/50/70 increased attack damage, 1 second stealth during Tumble, and triple the bonus movement speed from Night Hunter lasting 8/10/12 seconds.

FLASH-You make a mistake? You don't wanna die? Take this summoner spell,it helps you get out of almost any dangerous situation.
HEAL-Some may ask why not take barrier,yes indeed but heal gives a movement speed buff which is really helpful to escape or kite.