I want to ask why 
gets 2 items and than get's 100% crit chance 50% armor pen and still be tanky i am like wtf , and spells like 
W and W are unfair for the game W = doge all spells or AA, W = cant hit him with any projectiles
Yeah because he has 100% uptime on his BONUS armor pen right???
Why does fiora have % max health true damage an a built in invulnerability? :^) because slayers (melee carries like yasuo and fiora) need ridiculous steroids for their damage to be effective.
I agree about the crit chance. I believe that his bonus crit chance multiplier should scale up by level.
So instead of 2x at all levels,
Something like 1.4x / 1.55x / 1.7x / 1.85x / 2x at levels 1 / 4 / 7 / 10 / 13 /16
As for the Windwall. I do see why it is frustrating because it can definitely be an extremely valuable ability, ... but I really don't understand why everyone complains about it. It has a long enough cooldown, is almost always ranked last, and Yasuo doesn't often purchase CDR, so baiting it out makes Yasuo very vulnerable. Even then, it is not even a self shield, it is a directional shield. ... so WALK AROUND IT!
Otherwise his only means of defense is his passive, which is not really all that reliable either. He absolutely must get his defenses and sustain from items, and being a fighter means this is critical.
In fact, I believe he is the ONLY melee fighter with no built in sustain or resistances in his kit.
