I'll wait to see once his bugs get fixed and people stop rushing Static shiv on him.
There's no way he wont be broken at some point with that treasure chest amount of abilities.
Syndra's not exactly much less complex/diverse.
I can't help but compare his situation to Syndra. And Syndra also got major bugfixes too. I have not seen a Yasuo be successful at all. In any way. I see no reason to pick him over Tryndamere or Jax either who are far safer champions. Especially Tryndamere with his Crit-focus like Yasuo.
And you shouldn't be running a Riven and a Yasuo on the same team anyway. Yasuo and Riven are both awful junglers; Yasuo is not a good mid; and Riven is more like a niche counterpick to characters such as Fizz. Not to mention the fact Armor Hard counters them. Besides; the fact that Last Breath is activating on Knockbacks as well as Knockups [Such as Draven's Stand Aside] as far as I am concerned is
also a bug. It works both ways.
And yes; building Shiv first on Yasuo is horrible. OK; you're critting 50% of the time for say; 100 AD. So that's an average of 160 per attack. [Actually less since Yasuo has a penalty on his crits. I think it's -10% total crit damage so he would average 152 damage per swing]
I could have just gone BT and be averaging 170~200 depending on stacks. And my skills scale on AD. And I have sustain.
Admittedly Yasuo is swinging faster with Shiv; but he has no sustain; and Shiv's passive shock is most useful when there are multiple enemies. Not to mention Shiv's AS doesn't scale the damage of his skills. Your damage is also not reliant on RNG.