Hi im moutenn. This is my second guide, and i find making them really fun. My first was on Zed, so if you want to check that out as well feel free to do so here.
I am mastery 7 on him (like 50% of all league players), and thought that he would be a great for my second guide.
He is an extremely fun champion to play, which is why so many play him. You can perform well om him if you are good, else you are just going to get destroyed, by Zed's and LeBlanc's. Keep playing him and find out which matchups you perform well in and which ones you need training.
This guide is primarily focused on mid Yasuo, but i will also create a tap for top Yasuo.

Yasuo is a highly mobile fighter/assassin, who has enough singletarget damage to be a great dualist, splitpusher but also enough damage to take out entire teams. Yasuo has gotten a reputation, as one of the most toxic champions. Rumors are based on truth of couse, but the primary reason why he is played that much is that he is really fun to play.

If you want to check out some Yasuo plays click here or here

PRECISION:

Conqueror is the new keystone on Yasuo, since it allows you to deal constant free true damage, which helps against opponents going Ninja Tabi. Conqueror + the new Infinity Edge makes tanks cry. You do so much true damage, plus your ult that gives you 50% armor pen. You still need to remember that you need 100% crit, since both Infinity Edge and your Last Breath only works when you have 100% crit.

Triumph, is your best option here, and it allows you to be more aggressive. It will reward you for playing risky. Overheal you go if you have Fleet Footwork, because of their synergy. Else don't.

Legend: Alacrity, is down to preference. Because I rarely go Berserker's Greaves, the attackspeed helps out a lot. But don't get me wrong, all the options in this one is just fine.

Coup de Grace, helps out in midlane, because it makes you a little more assassin-isch. In top you should go Cut Down, because it helps you take on tanks.

DOMINATION:

Sudden Impact, is great since you dash all the time. So much extra damage. I guess you could take other runes here, but its my preference.

Ravenous Hunter allows you to heal of of your Q's, Which is a lot of lifesteal, combined with the lifesteal you also get on your Q is great.

Why these core items:




Phantom Dancer, is really great on Yasuo. His kit is really great with the dual aspect of the item. You make them do less damage, while you get 60% critchance. You can win so many duals with this item. When Yasuo came out you went Statikk Shiv, but Yasuo has so much waveclear anyways it does not matter. I always rush this item (unless you really need a hexdrinker)




Infinity Edge, is so good. Its a huge powerspike. You round out at 100% crit, and it boosts your crit damage even more. You can burst anyone, with it. You could get is as a third item if there is no other choice, but you should get it early.


Situational Items:




Statikk Shiv, you only go when you want to spice it up. Its just a worse phantom dancer.




Frozen Mallet is a great item, that allows you to stick to a target. It also makes you tanky, but still gives you damage. Its great, and i would recommend this is the enemy's have a habit of getting away.




Blade of the Ruined King, is a great item. It gives you everything that you want. It gives attackspeed, lifesteal, damage, stickyness (active) and more damage against tanks. All around great, and i rarely dont buy it.




Death's Dance is a weird item, but you could buy it. Its rarely good enough to buy over other items, but you could against a Zed lategame.




Guardian Angel, is a great item lategame. It allows you to be more in a fight. You could for example, engage with a great knockup and do a bunch of damage. Then die and resurrect when your team is there. Its great as a last item, or early if you are ahead to maintain your lead.


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Lord Dominik's Regards/ Mortal Reminder, are great if they have a one or more tanks who are a problem. With your ult's effect, you can get 85% armorpen! You will almost do true damage crits to them. Its busted.




Maw of Malmortius you buy against ap teams. If you are in a lane, with a Fizz or like such you can rush Hexdrinker. If both the jungler and the midlaner are ap, go Zeal - Hexdrinker, this will allow you to kill both of them.




Mercurial Scimitar, is great if they have dangerous cc, such as a Malzahar R Nether Grasp.




Ravenous Hydra, is a decent item. Its like a worse Bloodthirster, but its still fine, if you want to get some AOE damage. The active you can use while you E-Q, so thats nice.




Sterak's Gage, allows you to survive longer in fights, which is great, because you may get kills, which makes Triumph get you more HP. This plus lifesteal makes it really hard to kill you.




Trinity Force, is a great item. The sheen props on your Q, and the heath and movementspeed you get from Phage, is great. Its a bit better on top Yasuo, but still viable on mid Yasuo.




Titanic Hydra, is a fine item on top Yasuo. I dont really ever go this, but it helps for more tanky builds. The AOE and AA reset is great.




Black Cleaver, is great at shredding tanks. This plus Mortal Reminder and your R Last Breath, gives you 99% armorpen!. Thats pretty nice.

Skill Sequence mostly comes down to match-ups. Your Q Steel Tempest is great to max if you are against meelee champions or champions with no skillshots. You can max E Sweeping Blade if you are against champions with skillshots, like Xerath. I dont need to max E any longer (i did when i first started), because i dont need to spam it. It already has a cd of 0,5 seconds. When you first start you just dash-dash-dash-dash-dash, for no reason. When you are better you can make each E count so you can get more damage on your Q.

Flash is a must on Yasuo. The extra mobility, and extra play making potentiel is great. And besides, as much mobility as you have, it is not good for escaping ganks. Flash is used early to get kills and survive. Therefor it cant be replaced.




Ignite is a great summoner spell. It allows you to get kills, and to build your lead. Grievios wound, is also great




Exhaust is great against assassins, that you are kind of afraid of. Like Zed of Fizz, exhaust is great.

Pros:
Lane bully
Really good level 2
High mobility
Scales great
Flexible build
Shield allows him to win most trades.
Really low CD's
Wind Wall can block mostly anything you are against
High skill sealing
Pretty easy to pick up
Needs two items to get 100% crit
Can go in most lanes

Cons:
Easerly camperble
Only one CC ability, that is a skillshot and you cant always use it.
His R needs the target to be knocked up.
If you fall behind, you will stay behind (unless you get a really good roam)
If you are up against a champion like Darius, you only really have two abilities.
CC counters him hard
Often gets focused like were an adc
If you focus on damage items you are squishy

Abilities:

Way of the Wanderer

Yasuo's Critical Strike Chance is doubled. Additionally, Yasuo builds toward a shield whenever he is moving. The shield triggers when he takes damage from a champion or monster.

Steel Tempest

Cost: No Cost
Range: 475

A skillshot basic attack. After two successful Steel Tempests, the next fires a tornado that knocks enemies Airborne.

Thrusts forward, dealing {{ f2.0 }} (+{{ f3.0 }}) physical damage.On hit, Steel Tempest grants a stack of Gathering Storm for 6 seconds. At 2 stacks, Steel Tempest fires a whirlwind that knocks Airborne.
Steel Tempest is treated as a basic attack: It can critically strike, applies on-hit effects, is interruptible by crowd control and its cooldown and cast time are reduced by Attack Speed.If cast while dashing, Steel Tempest will strike as a circle.

Wind Wall

Cost: No Cost
Range: 400

Creates a moving wall that blocks enemy projectiles.

Creates a moving wall that blocks all enemy projectiles for 4 seconds.

Sweeping Blade

Cost: -
Range: 475

Dashes through a unit, dealing escalating Magic Damage with each cast.

Dashes through target enemy, dealing 60/70/80/90/100 (+60% Ability Power) (+0) Magic Damage. Each cast increases your next dash's base Damage by 25%, up to 50%.Cannot be re-cast on the same enemy for 10/9/8/7/6 seconds.If cast while dashing, Steel Tempest will strike as a circle.

Last Breath

Cost: No Cost
Range: 1400

Moves to a unit and strikes them repeatedly for heavy damage. Can only be cast on Airborne targets.

Blinks to an Airborne enemy champion, dealing 200/300/400 (+150% bonus Attack Damage) physical damage and holding all Airborne enemies in the area in the air for an additional 1 second. Grants maximum Flow but resets all stacks of Gathering Storm.For 15 seconds, Yasuo's critical strikes gain 50% Bonus Armor Penetration - this affects Armor from items, buffs, and runes.

Comboes

Q-EQ-E-Q-AA-R-Q-AA-Q-AA

This seems complicated, but hear me out. The first part is just on minions. You start of by Q'ing a minnion, then EQ to close the gap between you and your enemy. By doing this you will have your tornado up, and be on top of them. Then EQ the enemy (unless they have mobility - in that case just E and wait for them to dash - then Q after them) AA one time before using R, and when they land start using your AA's and Q's to kill them.

Q-Q-EQ-Flash-R-AA-AA

This looks really cool, but it is risky and hard to pull of. You start charging you tornado. Then EQ a minion, and when the animation is going on, flash on you enemy. The knock-up effect will land on them, and you will get a free knock-up, that you then can R on. Finish them of by AAing them to death.

Trading comboes:

E-AA-Q-E

You E in, then AA and instantly after Q, then E out again, before they can do anything. (you can wind wall on your way out to negate their damage)

E-E-Q-AA-Q-AA-Q-E-E

This combo is just to harass, by dashing in and AA them long enough to prop a few Press the Attack AA's. Then E out again.

Teamfighting with Yasuo is often not difficult. However when playing from behind, it can be tough.
When ahead:
When you are ahead on Yasuo, it is important to play around the Playstyle, you have chosen (often which items you bought). If you have gone full assassin, you should not go in first even though you are ahead. You will blow up with any CC. Wait for you to get in a good tornado/a teammate knocking 2 or more up/ getting a pick. You can get a pick easerly, yourself. Just dash in to a target that is out of line or farming in a lane. Remember it can be a bait. Then keep going. If you are far enough ahead you can just slice everyone down, and they cant stop you.
If you have gone tanky-isch, you can frontline great. You do more than enough damage with your Q Steel Tempest crits, and your ultimate armorpen.

If you are behind, you often should not try and dual unless you are sure that you can win. Other then that you should poke with as many tornadoes, as possible. Most of them should crit and do some damage. The thing about being behind on Yasuo, is that its not because you do no damage. You do. The enemy just does a lot more.
Dont go in on the first tornado. Wait for your team to be ready, or wait for the enemy to be low.

Q:

Your Q has a short casttime, so you can Q-Flash, and your Q will go of after you flash. By doing this you will be able to catch enemies of guard. They will think you Q in place, because that is what it looks like, but then you flash and they take the damage instantly.

Remember that in lane, enemies will always try and juke your tornado at all cost. So with poking with your tornado, always try and cast it on one of their sides. (Its often down - not always but often). But if you find out they are not the type that sidesteps, then just fire it straight at them.

Holding the Q: This Is really usefull, in most matchups. You get your tornado ready. (Keep in mind that this was more usefull when you could keep your Q longer). Start attacking them. They will desperately try and juke it. They will sidestep after sidestep, but not create any distance from you. So you can just have your tornado up, and keep AA'ing them until they use their flash or are in a position where you cant miss your Q. This almost always works. Especially VS champions that have counters. (Like Zed R).

Also dont always go in on your first Q. Its often not worth it, and Yasuo benefits from longer fights. Therefor its often better to keep kiting and Q'ing to get more tornadoes. You should go in on your second, third or maybe even your forth.

W:

Your W can block any projectiles. Therefor it is important to really mess with the enemy. If you know where the enemy jungler is and you have pushed up really far. Wind wall the enemy of of getting farm under their tower. Towersshots wont be stopped by it, so they will lose most of that wave. If they dare to step up to farm. Give them a nice AA-Q to the face.

When recalling on low HP, always keep your finger on W

Wind wall comes from where you are and then foreword. Therefor you can block things you did not expect. Always try and use it one heavy abilities. There is a good chance you can avoid getting hit.

The casttime on your W allows you to cast it right before or right after your Q. Only one animation will go of. So you can hide your abilities. So if you have your tornado up, you can W-Q, and the wind wall will be shown with the animation. But then the tornado will fly out from the wind wall, with no animation. This will catch many people of guard.
This however, also goes for your Q. You can also use tornado, and then right after use W. This is rare that it is useful, but i guess when you fight a Riven, that thinks she can use R when you Q?

E:

Your E has a set distance. This means then it does not matter where you e from. You will fly just as far. With other words if you stand far from them you will dash to them. But if you dash when you are on them, you will fly far past them. This is important to keep in mind. If you E-Q an enemy that you stand on. Its rare that it will even hit them. However if you stand away from them and E-Q its almost always a hit.
You can also use this to get over walls. In the jungle, you can use Gromp to dash over the wall (If you have the right angle and stand right on him) keep in mind its pretty hard to do in battle. It easier to do from the other side of the wall. You can also do this wit: Gromp, Wolves, Raptors and Crugs.

R:

You can use your R on more than one person. However only if they are close to each other when you press R (and if they are both are knocked up).

Lategame your R has a low CD. Therefor its great to use it against tanks. Not for the damage, but for the armorpen, it gives you.

Your R is a great one v two ability in lane. It is one of the best abilities to turn a dual, that might else have been lost. Also a passive of your R that most people overlook is that when you R you get your shield refreshed. This is great in most fights.

Remember that your target just has to be somewhat in the air to use it. Therefor you, can get in an AA or an E before you R. So - you can tornado-AA-R. This just maximizes your damage.

Leave your constructive feedback or questions down below!