Well this is my first buid for Jax and i hope u can use it as well as i did!

I wont be talking about runes cause i dont rely on them that much... getting armor pen or some speed is an good idea but i totally dont use them so no idea what u should pick!

On the side of masteries i have to go with 21/9/0 its better cause of the damage output and 15% more magic pen comboed with runes is verybadass!

Now as u guys can see i havent done anything with the boots cause its best to go Ninja Tabi cause of dodge and counter-strike BUT sometimes (rarely) its better to go with Boots of Swiftness (like against teemo, malza etc.) I prefer to go Guinsoo/sheen/trinity cause that way i get very high dmg output and when im aroun 12-13 lvl i got over 2k hp and very decent damage. Its good to get hextech around 16. I've let out 2 open slots u can go Bloodthirster and Berserker's axe or to go AP. With those items u can win 100%

First of all stop whining about Empower OK !? Yeah its cool high damage BUT it doesnt help u get the kill so i max out Leap strike first because it reduces its cooldown. At level 5 u can jump into battle and get out without any hp loss and harrass enemies. Getting once empower for last hitting creeps and counterstrike once for that nice dodge is also important.

mkay i know its 21/9/0 and i ve got ghost. SO ? u can go with ghoust or flash but exhaust is most important thing. Exhaust is gonna help u get the kill even late game.

Pros

* Fast killing, late game 100% tripple kill
* Not squishy and slow
* Very high nuking abilities
* Perfect anti-caster thx to ulty (Yeah pwning that badass Karthus now is a kids game just leap and pwn)

Cons

* If u get a stat like 0/4/0 and have less than 50 minion kills till 20 min just do alt+F4 no god is going to save ur helpless jax.
* You become a very high profile target after a few kills so getting a Banshee's Veil isnt such a bad idea
* Against casters u have slim to none chance of activating counterstrike in forest or anywhere away from creeps