Hello, my nick is Pall Mall 92 and I'm currently silver division player on EUNE. I am writing this guide to show you the build I'm using to utilize the best of Azir kit. It is my first guide, so any feedback would be appreciated. Enjoy reading. :)

Azir is a mid-lane sustained damage mage, who summons untargetable soldiers to extend his range of basic attacks and is able to utilize them to kill enemies from afar with many possibilities of repositioning.

Pros:
-Can farm from a large distance and soldiers deal damage in line
-Gapcloser with a shield, if champion is hit
-Scales well with CDR and health
-Decent ammount of CC synergises with Yasuo
-Uniquie mechanics
-Destroy turrets with Arise!
-Places turret to siege of defend on a ruins of one
-Reference to Goa'uld and Jaffa from TV show Stargate SG-1

Cons:
-Requires skill
-Early mana hungry, if spamming
-Soldiers doesn't procs on-hit effects (except Rylai's Crystal Scepter and spellvamp)
-Starting attack speed is horrible

Entire configuration is made purely for an AP midlaner. Spell Weaving is useless since his soldiers does not procs any on-hit effects nor they are not treated as basic attacks.

The reason, why I picked 9 points on defensive masteries is because of the gained little sustain from Recovery and survival with procs on shield with Veteran Scars and Juggernaut (since the build and runes includes HP).

Flash is the only viable option, since if gives you proper escape, if your w-q-e combo will be not enough.

Ignite helps you a lot to secure a kill and in most of the cases it is the only viable option for second summoner spell.

You can try with Exhaust, if you need another CC.

Marks:
Greater Mark of Attack Speed - gives you a nice boost of 15% attack speed (since you have very slow initial attack speed) to utilize damage from Arise! to farm or to kill.
other viable:
Greater Mark of Magic Penetration - this runes will deal more damage overall and will pierce through some of the magic resist, but your attacks will be little slower. It depends from you, what you feel better at.

Seals:
Greater Seal of Scaling Health - gives you a lot of additional HP, which will procs with Shifting Sands, giving you additional 32 points to your shield at level 18.
other viable:
Greater Seal of Armor - if you feel uncomfortable with additional health, you can take armor seals.

Glyphs:
Greater Glyph of Scaling Ability Power - they are superior to the flat AP ones since scaling ones gives you additional 11 AP at level 7. Also you do not deal outstanding early damage, so there is no need for flat AP glyphs.

Quints:
Greater Quintessence of Ability Power - gives you nice early 15 AP and are more viable than the scaling ones.

ABILITIES:

Shurima's Legacy - Azir's passive gives you 50% of additional attack speed for 40% CDR. It also gives you ability to place turret on the ruins of destroyed one - except at enemies inhibitors or nexus.

Conquering Sands - Azir's Q - soldiers repositioning skill to harass, retreat or to farm. You max it first since you gain increased damage and lesser CD. Grants you stacking slow in ammount, but not in duration. You can reposition soldier from great distance to opposite direction, but you can't put them further than your max range.

Arise! - Azir's W - soldier's summonning skill. This is your main damage skill. Summoning does not deal damage, only by right-clicking on a target within the range of the soldier. You always max this skill last, since it only decreases the respawn time of soldier stack and the damage is increased per level.

Shifting Sands - Azir's E - your gapcloser. In order to dash to soldier, you need to put your cursor DIRECTLY on destinated soldier. If the enemy champion will be on the tether between soldier and you, dashing will knockup them and give you shield - this one procs with 15% of your bonus health. You can use this skill to escape, engage or move through walls and you max this second.

Emperor's Divide - Azir's Ultimate - this skill places a wall, which is unpassable for enemies movement AND DASHES and also speeding up the allies who pass through. This skill also knockup the enemies. You can use it to block narrow passages, to disengage or to separate enemy team. You max it, when it is available.

SKILL SEQUENCE

Farming:
Place your soldier with W. Remember that they deal damage in line, so you can position them differently to either push or freeze the lane. If needed, you can place second soldier or you can reposition them with Q.

Harassing:
Just reposition your soldier or two with Q on your enemy. Try not to overextend, because you will get vulnerable and prone to ganks.

Escape:
Place a soldier with W, move him as far, as you can, wait until he reaches his destination, put your cursor on him and then press E. If you do it too quickly, you will dash to the place during the replacement, where you will not reach the soldier. If you will do it too late, you might not escape. This require practice and skill.

All-in:
Spawn your soldiers with W, reposition them with Q behind enemy and then dash to them with E. Right-click on them and if you need to - BBQ them with ignite.

Starting items:
Doran's Ring 2x Health Potion - sustain, survivability, damage - all you need to survive through early trades.

First back:
Tear of the Goddess Boots - you need the mana sustain to command soldiers and some speed to avoid potential skillthots etc.

Items to rush:
Ionian Boots of Lucidity-> Fiendish Codex-> Stinger-> Nashor's Tooth - gives you CDR, which has multiple use on Azir - it is converted into attack speed, also shortens your cooldowns on abilities and respawn time of Arise!. You also gain additional AP and even more attack speed to utilize damage. Remember - soldiers does not procs Nashor's Tooth on-hit damage!

Mid game:
Rylai's Crystal Scepter-> Archangel's Staff - Rylai's gives you decent slow, if you place soldiers properly, Archangel's gives you sustain and after fully stacked you gain additional shield for additional sustain during teamfights. This is pretty much your CORE BUILD.

Late game items:
Rabadon's Deathcap - amplifies your damage by a lot.
Void Staff - if enemies build magic resist, this will pierce through.
Zhonya's Hourglass - if you get focused too much, this will help you survive.

That's all folks.
If you have any suggestions, please write about them in the disscussion panel.

Thank you for reading :)