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.
This is a guide for somewhat experienced players, although this build will work with just about anyone. If you are farely agressive then this is the twitch for you. After testing this build multiple times, I've yet to see it fail. Follow this guide and you will become one of the most feared Rats out there. Mobafire build of: http://leaguecraft.com/strategies/guide/551,Twitch,+That+Rat+Bastard