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.
Ghost and Insanity Potion just give amazing movement. HP are garanteed with Rod of Ages because of the passive effect of Singed. Boots have to be finished first because of the movement. Buy after the standard boots a mana cristall. Doran's Ring can changed to Rylais Cristal Scepter. Also Thronmail is a good decision against many melees.