Solo lane Shadow Shaman is capable of an ability combo that can kill almost any hero in the game between levels 6-11, if he manages to get Serpent Wards while most other heroes are still level 3 or 4. This guide goes over the item and skill build that will allow you to take advantage of this. After 11 or so you can't solo-kill anymore but thanks to the farm and level advantage you should be a potent support and pusher for the rest of the game.