Hi and welcome to my second guide for a champion of League of Legends, Jax.
In this build i mainly focus on ability power but joining with a bit of attack damage. I believe that Jax should have some attack damage so that if after you use you combo of Q and next W you can take some more damage from your enemies when you're abilities are on cooldown.

+ One of the best fighter's around.
+ Jump everywhere with Leap Strike!
+ Hextech Gunblade nerf? No problem.
+ Do well if your team is average.
+ Counters tanky DPS quite well as he gets frighteningly strong the more he battles
+ Wonderful passive, allowing him to take the brunt of any carry's damage
+ Excellent pusher
+ Great DPS with Guinsoo's Rageblade and Relentless Assault stacking attack speed


- Can do 1v1 very well, but 1v2+ requires caution.
- Crowd Control is a real pain!
- Needs to farm HARD early-on.
- His combo is countered by Banshee's Veil, as it's passive will block all the damage from your Empower (W) + Leap Strike (Q) combo
- You run out of mana easily on early game
- If you fall behind its very hard to catch up again in terms of levels and kills.
- Able to be picked on by ranged early game

I choose to put those 21 points in Offense so that Jax can have the damage he needs when your abilities are on cooldown and so that his magic penetration is bigger.
Those 9 points in Defense are so that he can old his lane and so that he has a greater dodge chance.

The choice on the Greater Quintessence of Evasion and on the Greater Seal of Evasion his pretty obivous but i will explain anyway. It's for dodge chance to give a greater use of your E.
I choose the Greater Mark of Insight so that you Q and your W have a better damage and the Greater Glyph of Potency so that all your abilities have a greater damage.

I start with a Doran's Ring and aim right away for the Ninja Tabi for greater dodge chance (this is a must buy item when using Jax). Next i wanna get Guinsoo's Rageblade for the ability power, the damage and for it's passive. An item that you also must buy when using Jax his the Hextech Gunblade for the damage, ability power, lifesteal and speel vamp (lifesteal when you use abilities). Then you should wanna get the Lich Bane for mana, ability power and it's passive: "When you use an ability, your next physical attack will deal an additional 100% of your Ability Power in damage. This effect has a 2 second cooldown.", and since the cooldown is so low you use this passive almost all the time. Next for some attack damage i choose The Bloodthirster and also for some additional lifesteal. My final item his Malady for an additional boost on ability power, on attack speed and also for it's passive that makes your target have his magic resist lower and lower untill you have all stacks.

In my off-tank build i maintain the same items untill the time i would get The Bloodthirster. Instead i get a Madred's Bloodrazor for it's passive: "Your basic attacks deal bonus magic damage equal to 4% of the target's maximum health". Next i keep the malady and i think that since it takes magic resist it helps you have a great damage cause the Madred's Bloodrazor deals bonus magic damage. If an enemy champions get's tank real fast, you should try and get the Madred's Bloodrazor as fast as possible, before you get lich bane but onlt after you get Hextech Gunblade.

(I may not put health and mana potions in my build but they are almost always a good thing to have untill the mid time of the game)

I believe Flash and Ignite work very well with Jax, since the Ignite let's you finish off the enemy champions faster and the Flash let's you get close to them easier, or if they try to escape.

You can also use Exhaust instead of Ignite if you prefer to try and get kills from your enemies faster.

Ghost is also a good choice if you think that your Jax doesn't not need Flash. Ghost also let's you get to your enemies faster or if your enemies are pushing too much and you got to walk cause it's faster.

A spell that you may also use is Cleanse cause it really helps you when finishing off a champion and he has a stun abilitie or in team fights that you are targeted and they stun you to get you as the first kill.

My second guide, i just hope you like it.
Please reply and comment.
Say what i need to improve.