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.
A friend told me to make this for him so he could see if he liked how it works. I only use about half of the things in this build. I always go Ninja Tabi, Guinsoo's Rageblade, Void Staff, and work on Zhonyas. At that point someone has won. Do what you want, I like AP with Jax because hit AP ratio is quite spiffy.