It´s very important that you build Last Whisper very fast, because with your E most Champs can´t build enough Armor to counter it. Then go for a deff item, Sunfire Cape or Frozen Mallet, because you are to squishy for a 1on1 at your Lane.
Look what the enemy Team is building then for you next Items.

Try to use your Q to make Damage at the enemy Toplaner and push your Lane, but never forget wards and remember that the castercreeps dies after Q and one hit.