Why the **** would you bother necroing this?

What type of defense does AP Xin need most? Resistances! This makes the amount of HP you heal way more efficient. So you definitly have to run Zhonya's Hourglass and Abyssal Mask. Armor/lvl and MR/Lvl would be helpfull aswell. As start item, go Flask, gives most sustain anyway. After that, go for Seeker's Armguard and Negatron Cloak so you can actually defend yourself. Then upgrade them and you got a good base of defense, now you can stack AP with Nashor's Tooth, Lich Bane and Rabadon's Deathcap.

imo I would put 1 point into E.

Okay, i'll show you my way to play AP xin. First of all, i think the best way to play this is mid lane, or jungler. Because of your mobility, you can easily roam and help your team get feeded. Then, Ap xin is like unstopabble late game, if you have items, you need farms, top can be a pretty good lane, maybe with your build, but i'll explain why mid is better :
- Items like Wit's End suits better to an ap xin midlaner, and is incredibly powerful early game on ap xin.
- As i said it, you are more able to gank and roam early game if you are mid.
- You need a lot of farm to be useful late game, so mid is a good choice.

Then, if I choose to play mid, I'll play my xin zhao an other way, more tanky, because with your build, late game you are one shot by the carries, if they have CC. In addition, carries like Fizz can completly destroy you.

So, I'll buy first :
- Null-Magic Mantle if the enemy mid laner is AP and you cannot dodge his skills. Like Ryze.
- Boots if you can avoid these skill shots. Like Nidalee
- Doran's Ring if you want regen, but i dont think this is the best thing to do.
- And finally, you get Cloth Armor if the enemy midlaner is AD. Talon or Zed, for instance.

In all the cases, unless all the enemy team is AD, i propose to get a Wit's End. This item is incredebly better than the Nashor's Tooth early game. Then, generally go for a Zhonya's Hourglass, buy Mercury's Treads or Ninja Tabi(depends if the team is ad or ap) and then buy your Nashor's Tooth.
This is the 4 items i take early/mid game. If the game lasts, you have many choices :
- You can get a Randuin's Omen to simply go in the fight and shutdown the enemy adc.
- You can get a Lich Bane if you think you'll no be one shot and to improve your burst.
- Abyssal Mask is pretty good too, for exemple if the enemy ap carry is too fed.
- The Warmog's Armor can be a good choice.
You can also get Rylai's Crystal Scepter combined with Rod of Ages, to have a large hp pool, but no resistances.

Okay, you build is pretty nice too, but i think Xin Zhao ap is better as an ap unkillable bruiser.
And sorry for my poor english, I'm from france ^-^.

Thanks for reading this, it's 1:22 in france, time to go to bed, I hope you appreciated my way to see this champ, and maybe add it to your build, after a some testing !

As others have beat me to explaining some of the AP Xin Zhao confusion, I will put my input here. AP Xin Zhao and only AP will work, just not as good. You need attack speed for him to be any good at fighting. Also, with items like Hextech Gunblade and Guinsoo's Rageblade, you get awesome bonuses that go very well with Xin Zhao, even if there is AD, he still scales off of it and can put it to use. So although there is AD, he is still primarily being built AP.

Wow! I was not expecting so many people to comment on this! I have read all of your comments and have been thinking about those marks of attack speed and I do agree, those would probably be the best option. I am thinking the marks of hybrid penetration can work as well, but your main focus on AP Xin Zhao is to use your auto-attacks a lot. So yes I will switch those marks over to attack speed, thanks for the feedback!

ap xin zhao is ap/as xin zhao in reality. "real" ap xin zhao would not work

It's not true AP Xin Zhao...
It's more like hybrid. Lol...

i'm not sure if this will work, i 'll try it and come back to vote

I think Greater Mark of Attack Speed is the best choice, because of the rapid heals.

earyl on you have great harras in form of your q, so i would say hybrid penentration or attack speed.(maybe even armor penetration? only your e deals magic damage. I don't play xin zhao, so i can't really tell if it is good)

You just should change the Marks to Greater Mark of Magic Penetration (or Greater Mark of Hybrid Penetration if it's stronger on AP Xin, don't know) or Greater Mark of Attack Speed!