Yasuo needs a pretty significant power shift in his kit

His lane phase is simply too good. Meanwhile, what he was intended for was largely to be a good skirmished and decent 5v5 melee champion (see windwall plus his ult). While he's a good skirmisher, his teamfights is completely overrated. Yasuo ults in, exhaust him and he's non next to nothing. Proceed to focus him and he won't accomplish much.

It's ironic. He was designed for teamfighting but it's his lane phase that just ends up being the problem. And you can blame phantom dancer, you can even blame FM to an extent. But yasuo has been problematic since he was designed and it has always stemmed from his lane phase. When he's weak, he's not good in lane. When he's a thing to the contrary, he's massively overpowering in lane. There's no in between and that's because his kit rewards him with too much stuff to ever really be balancable in lane.

I don't blame his passive

I don't blame his lack of mana

I don't blame his Q

I don't blame windwall

I don't even blame his ult (though it needs a significant CD increase)

I blame his E. His E is what makes him completely ridiculous. As long as minions are around, you can't be near him. Because his ability to close a gap, CC you, damage you the retreat back through a wave to safety without you being able to retaliate is what makes him do overpowering. And in top lane, with his non existent cooldowns and shield, he can stand on minions and bully 90% of the top lane roster into submission simply by spamming Q on you and then doing the above mentioned with his E. The other 10% that he can't just Spam Q and win? His E grants him the ability to massively outplay them all.

When it boils down to it, there's no answer for a well played yasuo in lane. And I don't blame his "overloaded" kit because it's all stats that can be out stat'd or it requires him to actually interact, both things are fine. It's his E. And no amount of nerfs will change that. You'll either nerf everything else until he's garbage or you won't and he'll remain broken.

I would suggestion putting a cap on how many times he can dash to enemy units then have the ability go on a short 10-20 second cooldown. Then once it's maxed, his E becomes the way it is now where there's no cap, just the cooldown on the enemy he can use it on again within a certain timeframe (this would stay on previous ranks too).

So for example, I'd do this

Rank 1 E: Yasuo can dash to 5 enemy targets, with 3 seconds being the maximum amount of time he can hold onto a dash without the spell going on cooldown. After using the 5 dashes or not using a dash within 3 seconds, Yasuos E goes on cooldown for 15 seconds. And naturally, as I said, he'd still have the cooldown of how long he can use his E on the same target again

Rank 2: 6 enemy targets 13second CD

Rank 3: 7 enemy targets: 11 second CD

Rank 4: 8 enemy targets 10 second CD

Rank 5: no limit, no CD

This would actually decrease his lane power a ton without murdering his ability to lane. It'd give him less outplay potential and more Windows of opportunity to be exploited.

I would also increase his Ults level 1 CD by 25 seconds. The fact he can use his ult simply to harass because the cooldown is laughably low is pretty bullshit.

Ideally, this change would make him weaker in lane and as a result, you can look at doing things to make his teamfights consistently better. You can buff his shield mid-late game, you can buff his scaling stats - anything that would improve his teamfight after lane phase.

He's just not a healthy champion currently. And his designs intention has gone into complete reversal and with these changes, I think you could allow him remain remotely the same without him losing a huge chunk of stuff.