You get 'swift as the wind' so that you can move around you enemy faster and make them miss their abilities.
You pick 'dogde' so that not even an enemy greymane can kill you when he jumps at you.
At lvl 20 it will be really hard for your enemy team to stop you!
However this build is very risky if you play it in higher rank than diamond.

Your counters will be:
-Varian (taunt)
-Uther
-Alarak

Don't think about the counters unless you play in master.