Early is kinda weak if you start with tear, but gives you a lot of healt and mana sustain. you can start to do something after you rush duskblade, but the real damage will be real only after muramana plus sheen.

Doran blade start will make you lose 5 minutes more or less to rush muramana, but gives you a good lead early if you want to stomp hard in lane, if you don't feel safe to kill or win lane, just go tear. 2 pots gives an huge sustain