WELCOME!
Hey there! I am Pòrnstar Yasuo, playing on EUW Servers. This is my first build on mobafire, i tried to do my best in this, and i hope you enjoy this. I main Yasuo since Level 25 more or less, and now i am on lvl 30 since December 2014 :).
Let's Start!
If you don't know who i am, check out my best Yasuo montage here: Play Video (Last clip wasn't yasuo, but you didn't see nothing :P)

WORK IN PROGRESS

go for this if you have a matchup with a no-skillshot based champ go for this if your enemy is skillshot based. You have more mobility too.

Usally spells for midlaner.
= For escape or engage.
= Secure kills in dives at lvl 6

PROS

-High mobility in lane -A lot of early damage outpout -Double Crits for free -Very good passive. -Unkillable late game

CONS

-Very vurnerable without shield -A little bit squishy -Focused in team fights maybe more than Adc's.

The following abilities have Crowd Control effects classified as airborne and thus, interact with Last Breath:
Aatrox's Dark Flight
Alistar's Pulverize and Headbutt
Anivia's Crystallize
Azir's Shifting Sands and Emperor's Divide
Blitzcrank's Rocket Grab and Power Fist
Braum's Glacial Fissure
Cho'Gath's Rupture
Diana's Moonfall
Darius's Apprehend
Draven's Stand Aside
Fizz's Chum the Waters
Mega Gnar's GNAR!
Gragas's Explosive Cask
Hecarim's Devastating Charge
Janna's Howling Gale and Monsoon
Jarvan IV's Demacian Standard + Dragon Strike
Jayce's Thundering Blow
Kalista's Fate's Call
Lee Sin's Dragon's Rage
Lulu's Wild Growth
Malphite's Unstoppable Force
Maokai's Arcane Smash
Nami's Aqua Prison and Tidal Wave
Nautilus's Dredge Line and Depth Charge
Orianna's Command: Shockwave
Poppy's Heroic Charge
Quinn's Vault
Rammus's Powerball
Rek'Sai's Unburrow
Sejuani's Arctic Assault
Singed's Fling
Shyvana's Dragon's Descent
Syndra's Scatter the Weak
Thresh's Death Sentence and Flay (Active)
Tristana's Buster Shot
Trundle's Pillar of Ice
Probably bug: both allied and enemy pillars will work.
Vayne's Condemn
Vel'Koz's Tectonic Disruption
Vi's Vault Breaker and Cease and Desist
Volibear's Thundering Smash
Wukong's Cyclone
Xin Zhao's Three Talon Strike third strike only and Crescent Sweep
Yasuo's Steel Tempest (Third strike only) and Last Breath
Zac's Elastic Slingshot
Ziggs's Satchel Charge
Zyra's Stranglethorns

WORK IN PROGRESS

So guys i hope you enjoy this guide, sorry for my grammatical errors, i'm from Italy and English is not my main language.
See you soon!
Pòrnstar Yasuo.