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.
I recomend to use this build if you get A LOT(seriusly a lot) of kills. The damage at 20 stacks both is trully awesome. About Dorans shield: use it for early survivability. If you don't need it skip it. Of course in the end you swap it with the 2nd Rabadon, or maybe hextech gunblade.
The potions aren't an obligation, buy them if you have to return a lot early-it will save you from being outleveled(sometimes), still it's better to port back if you think the potions aren't enough.You also can use hextech gunblade earlier, but after you get Mejai's soulstealer and Sword of the Ocult.
To be updated...