This is also my first build on Mobafire so if you could leave comments it could really help
This is a hybrid build which will help at you against tanks. They will have to try to build of both defenses, which will make it hard for them to do.

You really want to try and build armor pen so you can take out those tanks. Also you want plenty of attack speed when ever your in lanes so you can farm quite fast

Same thing as the runes, be as viable as possible. Attack and Defense are key to success with Jax since that is where he can be a little weak. If you are fed however, you can 1v2 or even 1v3 enemies without dying. By fed, I mean you are carrying your team and have a decent amount of kills, 10 or so is good enough, although I often get a lot more. This build has the capability to get you 20+ kills, or even 30 or so. So like I said, be viable, you can confuse your opponents and beat them.

Your skill sequence is very simple, before you engage a target you want to activate counter strike a bit before leaping so you can lock them in place and then use your empower. you want to get as many points as possible on your leap strike as it is one of your most powerful abilities. I would recommend soloing because it is the more levels you gain the more powerful you become and you can also escape ganks quite ez by using your leap strike.

For your masteries you want to try and close as much distance as you can between you and your target. I would recommend that you get flash and ghost. Your leap strike can help you close distance as well in lanes. So a leap strike to a minion then flash to your target can help you get your stun out.