Early Build Priority vs Physical
Early Build Priority vs Magic
Sample Core Build
Teleport is viable in certain situations.
Talon has highest first blood conversions in game, thanks Riot!
Edge of Night is great if you don't need Guardian Angel or Mortal Reminder. Can also be swapped for Duskblade of Draktharr if you're terrified of magic damage. In that case, Maw of Malmortius is also a good option, especially with a laning Hexdrinker.
Boots of Mobility are great if you gain a lot of early lane control and want to transition that to other lanes more easily.
Sterak's Gage is your Maw of Malmortius vs. mixed or physical damage. Great in combination with Guardian Angel and Ninja Tabi for becoming relatively tanky.
Infinity Edge is your melee range 1-shot button. Good against comps that want to engage on you. Not much room to fit into the build, though. Very high damage, but also very high risk. Not usually worth it.
Lord Dominik's Regards is your Mortal Reminder Substitute vs zero/low sustain/healing.