Yuo will have to buy Vampiric Scepter so that when you when you are trying to deal some damege to enemy to let your jungler come and have a succesful gank. It will mainly help you retreat to your tower and gain Hp back by killing incoming minnions. as soon as you can buy Wriggle's Lantern it will help you see if any one is in the bushes and so that you would not have to go in there inorder to jump enemy but jump from the safe distance and it gives you extra armor to survive in battles. Depending on the enemy team you will have to by ninja tabi or Mercury's Treads. The Black Cleaver will help you will damege and attack speed and to reduce your targts armor, this will be very helpful agains tanks and any player who builds armor to counter you. Last Whisper will allow you to deal damege and penetrate your enemyes armor, this will be helpuf in fighting with squishy targets. Phage will let you stay in fights longer and slow your targets to catch up to them if needed.