Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Lots of attack speed, it will get you to the cap attack speed of 2.5, adds some life steal, movement speed, and attack damage in order to kill faster. Basically spam your ultimate, and spam W, throw in an occasional E to slow them down, and use Q as they run away for some extra harass damage. Other than that it's pretty simple.