if his windwall was reworked as such:
Yasuo slices the air in front of him, creating a gust of wind that continues moving forwards slowly for 2 seconds, blocking any projectiles that would pass through it.
this allows both for more realistic mechanics and more timely interactions between players. I feel a shorter cooldown might be needed since the window of safe time for Yasuo after casting his wall is much shorter. slightly limiting his overall defensive power at any moment's notice could allow for more interactive combat and more offensive tools.
if his ult was reworked as such:
**Now has different effects based on how many stacks of gathering storm Yasuo has.
Ultimate cannot be cast without first having at least one stack of gathering storm ready to cast, nor can it be cast off of allied knock-ups.
With one stack of steel tempest ready to cast, Yasuo's next basic attack is enhanced. Steel Tempest can also proc this attack. This puts the ult on a 25-second cooldown. **
I feel that manipulating the areas where Yasuo is weak and ineffective as a champion would allow the balance team to follow up with more reasonable and manageable weaknesses that better suit his theme, as well as leaving the champion in a state that is still fun for the community that enjoys his amazing playstyle. I feel this is a possible way to address Yasuo's skirmishing power so that he does not feel so punished for trading when behind, as well as allowing less complicated combos to be learned and used by those trying to begin learning the champ, and new ways to trade reasonable damage while offering more options than ONLY all in's/feeding heh or hiding under tower.
this way the lane is more interactive and interesting after the first few levels, instead of being either Yasuo got fed or Yasuo died trying to get fed because he will be worthless to the game if he isn't fed, and can now no longer walk up to farm or try to get back in the game
Upon knocking up an enemy champion with the 3rd stack of gathering storm, Yasuo's traditional ult can be cast. Instead of Armor Penetration, Yasuo will be granted bonus damage based on a percentage of his missing health
I think this is a good way to reward the high-risk behavior Yasuo's players usually follow while also making his damage more situational.
while low health outplays feel very rewarding when I'm playing him, the all in from the full health 4/2/0 enemy Yasuo shouldn't feel quite this ridiculous to my lane as soon as his pd is acquired. having such an ability to take over a game should not come so easily. His theme as a lone, wandering swordsman means he should be effective by himself. so naturally, his dueling should be good, but being able to follow up on a knock-up 14 teemo's away grants him a power that doesn't suit his solo playstyle. being able to execute combos based only on his own prowess limits his total threat during the different points in the game, while also providing some tools to allow more opportunity to trade for less experienced players. with this, numbers can be balanced better I do believe.
sorry for such a long read, i can be passionate about how my favorite champs are approached, and im not the only one.