Hi there, I'm sphaxwinny, currently plat in EUW and this is my 1st guide ever, so i hope you'll enjoy it, and if you don't, you'll help me to improve it.
Remember while reading that this has no other pretention than been a "guide", not a "do so because I say so", nothing is set in stone, something can be perfect in some situation and really awfull in a different one.
I'm looking forward to get some feedback, either good or bad, and to keep updating this guide taking your commentary in account.
I'm also french, so english isn't my native language. Please excuse me if I don't write it very well.

Azir is a weird champ, an ap carry, but yet relying on his autoattacks to deal damage, but not in the way kayle or teemo do so: all his gameplay is centered around his soldiers, summoning them and replacing them in the right place.
I have to change this paragraph but don't have the time atm, I don't really feel like grail or morello being still useful on azir.
I know some people do really like to go on a grail/morello build, but I really prefer a nashor build, with a tear for the manaregen.

I once used to build a grail/morello as well, but I think your damage output are really higher with a nashor tooth, even more with the base AS we got in 4.18.

But before going further in the build itself, there is Azir's main strenghts and weakness:

Strenghts
*Large amount of damage late game
*Insane turret damage
*One of the best peeling ability with his ultimate
*All of his kit is AoE making him a monster in jungle fight when the opponent team is packed
*Easy to farm with (except first level when you have a bad AS and can't spam soldiers)
*Can pop a 1-min turret every 3 mins, helping sieging
*Good roaming power
*Is the god of birds

Weakness
*When falling behind, it can be tricky to catch up
*Still very buggy, you have to care about his non-damaging soldiers
*Can pop a 1-min turret every 3 mins, giving opponent team 100 gold if poorly placed
*Hard to play, with all the soldiers positioning things and timers to keep in mind

I'm currently trying different runepages, but i usually go with an ap rune page:
Quint: Flat AP
Red: magic pen
Yellow: scaling HP
Blue: flat ap

Of course this isn't set in stone, you'll go MR blue against some mid, etc, but this is the page i use the most.

I'm trying many different settings atm such as AS quints, 6 blue cdr to be capped with nashor + elixir/blue, AS red and such things, and i will update this section when i'll be done with it.

Not much to speak about here, I tried the 21/9/0 masteries but i didn't found that the little extra survivability was worth giving up the runic affinity nor the summoner spell CDR.
If you're thinking you're taking too much damage you can still go for it.

PS: i'm taking butcher and arcane blade for all the early farm you'll do without your soldiers, but if you're confident in your lasthitting skills you can go for 2 points in fury instead.

Maxing Q first is the way to go. You'll be able to poke opponent, slow them and reposition your soldiers more often, there is no reason to not max it first.

People often wonder if they must max W or E second. I think that you don't really need more soldiers than what you have with 1 point in it, except if you want to push turrets really faster, so i usually max E second for the CD, damage and shield it provides. If you're splitpushing all day, you can consider maxing W second, but it's not really worth it most of time.

This is your bread and butter skill. It allow you to place your soldiers where you want, damage opponent and slow them. It may be a little hard to get how soldiers will interact when you have multiple of them out, but they'll usually cross their way a little before their targeted location, allowing you to hit your opponent multiple times (only worth 25% more damage, but every single piece of free damage is worth taking).
Also remember that if you move a soldier from too far away, he may no longer deal damage when auto-attacking with it (it's a bug being taking care of), the safest solution is to try to minimize their travel time (a thing you should even without any bug: less travel time, more auto-attacking time, more damage).

Not much to say about it, it spawns one of your fellow soldiers, allowing you to play with your other spells. Try to always have at least 1 soldier stored in lane, in case the opponent jungle ganks you to be able to perform a quick W=>E combo.
It's also hurts turrets pretty hard, but take care not to be unarmed when near the opponent turret, making you an easy prey.

An amazing escape tool, and good engage aswell. I'm using it frenquetly in lane to get early kills and to gank others lane. The shield is pretty strong too, allowing you to do some crazy all-in in lane, but take care of opponent's jungler.

That's an ultimate for you. Dealing damage, boosting your team movement speed and blocking opponent team. And buggy as hell. I can tell you that if you're going to play azir, you'll love this spell but also hate it cause of the weirds things it does. People can be bumped by it but still be in your side of the wall, some can pass freely through it, the soldiers it summons have weird placement when they are walls nearby etc... But still one of the best ultimate ever, a game-changing one, especially against assassins, who need to stick to you to deal damage. W=>Q=>E=>R would be one of the best engage ever if it wasn't so buggy and if Azir was a tank ( you can still build him as one but i don't really like it).
Also usefull to disengage or to protect a dragon/baron from the ennemy jungler.

I usually go in with doran rings and 2 pots not really much to say about it, you can consider getting a cloth armor and 5 pots if you feel like you'll lose your lane against an ad champ.

I changed my mind about the grail build, I highly recommend a nashor build, but I don't plan to erase the paragraph I once wrote about grail, it may interests somebody.

Attack speed one:
=>=>=>=>
With this guide, I try to maximise my damage output, relying on my range and defensives CD to stay alive. With a blue pot or a blue buff, you'll get to 35% cdr, and that's why I don't recommend going on luciditys boots, go instead on sorc/merc/tabi depending on the match-up and such things. With a tear, you'll have more than enough mana to play arounf with your soldiers, and when you get a blue you'll be able to hit Q on CD without getting nearly oom. Always try to poke the other team before engaging a teamfight, a Q followed up by one or 2 autos are really scary for anybody, once you got your nashor void staff and archangel. Save your ult for defence, you're not tanky enough to engage a fight and survive after that, even with your shield. You also are an awesome splitpusher due to your W doing insane damage to turrets and your quite high dueling potential (the only one who can really afraid you are burst mage as Annie and Syndra, melee assassins being zoned by your ult and tempoed by your defensive CD.

Poke one (I feel it is outdated but you can read this if you feel like it:


Of course those item paths are not set in stone ! They are merely guidance for new Azir players, i frequently go for an mix of both. If i know i'll be having all blue buffs, going nashor/void/rylai/rabadon.

There is many item that you can also consider as abyssal scepter, ROA, GA or even more tanky items, but it's all up to you to go on try it, I'm currently testing to many things to consider it at the moment.

Many people are coming speaking about the nashor tooth being uneffective because azir doesn't use its passive when attacking with soliders. But even taking that into acount, nashor tooth provides to much stat for not being efficient on azir. Let's do some maths:
a dagger, the basic attack speed item provides 15% AS and costs 450, so 1% AS is worth 30 gold. One needlessly large rod provide the most ap/gold and give 80 ap for 1600 gold, so 1 ap is worth 20 gold. CDR is harder to speak about, because no basic item provides it, but from the codex and the kindle gem, we can say that 10%CDR is worth about 300 gold (a little more but it doesn't really matter) so 1% CDR is worth ~30g.
Nashor tooth gives 60 AP, 50% AS and 20% CDR, adding 25% AS.
That is 1200 + 1500 + 600 + 750 = 4050 gold if we value the stats as stated before (inb fact even a little more, because I rounded all the statweight down) making it a pretty efficient item.
Some people will oppose that Azir has the lowest base attack speed of all champs, which is true, but a nashor tooth still allow you often to get 2 autoattacks after Qing somebody, incresing by much the damage output potential.

I'll be editing this, still gathering information about some champs who aren't often played. This section is about what I feel going against some champ, it may not match what you are thinking, feel free to comment and explain your point of view.

Morgana


Zilean

Azir has a decent laning phase, being able to farm from far away helping him to deal with hard match-ups. Remember that early on your W=>Q combo burns your mana really fast, and isn't really mana worth if you cannot land at least one or two autos after it. Hitting your opponent with soldiers will also aggro the creeps so take care of them.
You have a pretty decent all-in potential, especially if you can take lvl 6 before your opponent does, and even before that, you can burn them out with an ignite pretty fast if you manage to land a bump on them (I often grab a kill lvl 5 with a W=>Q=>E=>ignite=>auto=>Q combo, but once again, take care of opponent jungler). As I said before, try to keep a W stack and your E in case of getting all-ined or ganked, and do not greed it is hard to see you opponent escape with 20 hp, but it's better than seeing him escape with 5 while you're lying down on the ground.
After your first backs, keep trying to push your lane in order to roam or to farm your jungle, your wraiths can be easily toyed with, by playing with their aggro range.

As Azir, you have 3 goal in teamfights:
*do damage - of course you're an ap carry.
*peel your adc - can easily be performed with your kit.
*stay alive - cause you'll be able to deal more damage that way and you can push towers and get objectives very fast.

Of course, the priority is to win the teamfight, even if it mean your death and your adc's, but it's better to be able to do something after it- pushing and taking objectives is harder if you don't have a carry to damage them.
With 40% cdr your Q is on a very short cooldown, try to use it as often as you can, but without loosing too much autos: all the time they are traveling your soldiers cannot attack, making it hard to move them too often. You'd better pop one close to you if somebody dive you than to make the soldiers you've already sent on opponent's carry come back to you. Also try to get one soldier stored in order to be able to react, not being able to defend yourself cause you summoned another soldier on some people is really sad. Keep in mind that 2 soldiers hitting the same people is only 25% more damage than one, better than nothing but I'd rather cover a larger space than hitting a little more, when i'm already able to 3-shot opponent squishies.

I'm currently gathering them, i'll be updating it soon. Here are the ones I noted for now:

*Your E send you before your soldier, remember taking it into account when engaging/escaping.
*if you play with smartcasts, pressing your E will send you to the nearest soldier of where your cursor is, even if it's in the opposite side of your screen.
*Your turret's health is decreasing over time, try to place it as late as you can, in order to have the maximum health when fight is engaged.
*When running away, use the W=>E combo to escape, then use your Q to slow opponents if they go near your soldier.
*Your ult is amazing for the crowd control it provides, but if you are in a 1v1 situation, you can use it for the burst it gives you ( more or less 500-600 magic damage @level 16)
*Your soldier gives vision, making them one of the best bush checking abilities.
*Few ultimates can pass through your ult: Vi, Malphite, Nocturne are the ones i noticed but it may not be all of them.
*I think the best lane to put your turret up is midlane, cause they are more close one of each others.
*Attacking with your soldier actually proc the enchantment furor, making it viable on azir, even if you'll usually go on homegards one.
*YOUR ULT IS BUGGED: it has a knock-back. But! it will not cancel channeling spells (except recall/teleport) - see this video: https://www.youtube.com/watch?v=nDqHOm4vVGs&feature=youtu.be&list=PLMu2BWlXk_bEWj2WnhJQ6YgiqxcO1mEBm

Send me any screen shot of how well you did in actual games, I'll send it here if they're worth it to show.

Hope you enjoyed reading, keep in mind that this guide is not finished, I still have to complete sections of it and I'll be updating it often.
Please leave a comment if somthing is bothering you, I can perhaps fix it.
Feel free to post what you think I can improve / what you think is great/awful or whatever is on your mind.

22/9/14
Release of the guide.

23/9/14
Adding a little bit theoricraft about nashor tooth and this wonderful section.
Change of introduction.

2/10/14
Added Zilean match-up

9/10/14
Changing my point of view about buildpath due to patch 4.18

12/10/14
Added Morgana match-up

13/10/14
Changed the item section and did some minor corrections -remember to signal me any problems about syntax or such things!

16/10/14
Edited some little odds sentences