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.
Start up with Doran's Blade and a health potion. Later buy berserker grieves following sword of the occult. Later buy a last whisperer and a bloodthirster. Next buy an infinity edge. Sell your doran's blade and buy a phantom dancer. And finally sell your shoes for another phantom dancer. Your damage output is so high and a high crit chance that now your crits will hit about 1k. Also take in consideration I'm taking count of sword of the occult with a minimum of 10 stacks.