At first you buy Boots and Potions like everytime then you go on Blade of the Ruined King(Cause it makes more damage then a full stacked Bloodthirster).In late game you can choose your own last Item but i settted some examples. Buy Black Cleaver for a tanky team, buy Last Whisper if your enemy goes hard on defence and buy Guardian Angel if the enemy team focus you hard in teamfights.

Have fun while trying my Guide.