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.
This build mainly focuses on getting your team kills and around the map real fast. I've yet to lose a game using this build but i'm more often then not in a negative kill/death ratio. Most games end by the time you get GA too. Just tag along with your dps and make sure those free kills don't get away easily. Your ulti will be on around a one mintue cd with max CDR and you'll have around 70% magic damage reduction.
With your E and the active from revirie you'll be flying "littraly" around the map.