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.
Flash is a must.
Teleport, depends if their team has split pushers/fast pushers.
Exhaust whenever else.
AD is neccessary. The CD gives you 10 cdr, combined with 20 from BC, and 10 from DD, you got 40% CDR. Makes you unstoppable.
He is able to speed his entire damn team, then burst any squishy in his wake, like a Sivir ult but better.