Yasuo's kit overall makes no sense. Riot has changed him so many times to keep his double crit chance. It makes no sense to be in with his kit. His dash shouldn't do damage. However it should give you flow based on the level of your e when you dash. Continued use would give less flow. His q is fine how it is. The scaling of it is fine since it has a low base damage at max rank. His W should drain his flow. The more flow he has the longer the windwall stays up and the more damage it takes. Make it so that it can be reactivated to cancel so that you still have flow when it's not being used. The CD on it is fine how it is i think. People have also been complaining about the armor pen his ult gives him. I think it's fine to give him that but reduce how much it gives. It was meant to make tanks not super tanky. Since it's against bonus armor and not base. That means that tank get killed faster but carrys get killed just as fast as before.
Summary
*Remove his double crit chance. It makes no sense.
*Q is fine
*Make his W drain his flow. Make it able to be reactivated to cancel it to keep some flow.
*Make his E do no damage but give percentage of max flow. Say 5% max flow at max E rank. Making it give less for continued use. Say up to 50% less for continued use.
*Remove or reduce his armor pen from his R. It shouldn't be as much as it is since when he get a Last Whisper it makes it unfair for tanks.