A Weapon build focused on 2. The play style is to take advantage of sharpshooter and RoA to fight at a height and distance many characters have trouble reaching. Really good in teamfights but you can 1v1 a lot of the cast if they don't have a counter item for you.
You start doing good damage towards the end of the mid category but really get nutty after Vampiric + Blood Tribute.
I personally save early AP for 2 ranks ulty to try and stack/impact the map. If that's not your thing then you do you.