Yasuo Wind wall Bug

Could be a bug indeed, since it's a ranged attack.

Though, here's a potential theory. Wind wall blocks projectiles, and azir's auto is, strictly speaking based on the animation, not a projectile. It might not be the case, it could just be a bug, but just throwing it out and let's see if we get an official response.

Azir, Vel, and Thresh all have ranged autos that aren't projectiles, so they go through windwall

https://www.youtube.com/watch?v=qq0VbJOkREo intended.