You need +9 armor seals, so you take less damage from the enemy ADC in early game, 8.5 extra AD marks, so it?s easier to CS in earlygame, and MR glyphs so Vayne can survive AP supports in botlane. Lastly, you extra 13.5% attack speed these quints grant, so you can auto attack faster, and easily get third? Silver Bolts-shot.
Always get these in laning phase.
Cull vs Doran’s blade: When you look at the stats, Doran?s blade is clearly better. However, an ADC has at least 75 AD during the first minutes of the game, and considering he lands 15 auto attacks(on minions or on champions) per wave, the 3 life on hit instead of 3% life steal gives the Cull ADC a little above 10 health points more per wave than the Doran?s ADC will. These won?t matter on fights of course, the regen difference will not even be noticeable. Cull grants you a 400 gold difference from Doran?s blade. However, getting Cull is a gamble. If you lose your lane, you won?t be able to get its passive gold early and Doran?s blade is a better choice to keep it safe. Not only is it safe, but you get a little additional hp and better lifesteal scaling if you get your first item. It is just more useful, even till late game.
Blade of the Ruined King: Getting this item first is always a good choice. However, Infinity edge is also good if you are way ahead. Getting Botrk early grants a huge powerspike. Pair it with your Silver Bolts and you can deal a crazy amount of damage early. If you are against a tank support you can get? Bilgewater Cutlass early, so you can use the active skill to deal extra damage or a slow effect. I don?t recommend getting the Recurve Bow first.
Infinity Edge: Grants Tons of damage! Buy this after two Attack speed items, such as Blade of the Ruined King and? Phantom Dancer.
Berserker?s Greaves: Even more attack speed! And movement speed as well! Should be bought after you buy Botrk.
Blade of the Ruined King: Grants sustain, attack speed and damage. The active is always good for kiting and getting the advantage.
Rapid Fire Cannon: Lots of AS and and critical strike chance. Has a pretty painful passive too.
Statik Shiv: Lots of AS and and critical strike chance like Rapid Fire Cannon but has an AoE passive that is pretty good when clearing waves.
Lord Dominik?s Regards: Very handy when you meet some heavy tanks, and some extra armor penetration is pretty good.
Berserker?s Greaves – Furor: Get the furor enhancement if you are ahead. It will give you a small burst of movement speed every time you auto attack.