Some simple changes (not too much) would be fine to make him less overloaded and annoying to deal with. Think similarly to removing akali shroud under tower or removing irelia's triple damage to shields. I might be going a bit too easy because im level 7 with him, but i really think these could reduce how frustrating it is to play against him.
**Removed**: Yasuo's ultimate no longer teleports him outside of the turret's range. If he is within the turret's range during the knockup of the ultimate, the tower will target him.
**Bug Fix**: Yasuo cannot cast windwall while dashing just because he cast q (yes this is a real thing btw).
Let me know if you have any other ideas as well, these are just the ones i could think of.
**EDIT**: Removing knockup on allies would be too much, i went overkill with that one