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.
Buy "Sword of the occult" if you want to be offensive.
If you are more the defensive person, buy instead "Frozen Mallet"
Hints and Tips
Normally, if you are mid, and are playing against a range-champion use "Hit and Run" for example. If you dont know what "Hit and Run" is then its, when you run over to your enemy and shot/attacks and run back, and do it over and over again.
Don't be scared to use your ulti, cause the "Nashor's tooth" have 25% cooldown.