Yasuo bug

Yasuo while using his e is immune to aura damage effects like sunfire cap/shyvana w and it will not pop his passive in a custom game I even tested where he can do 3 e's in a zig zag line where he is near aura effects for a few seconds while spaming e it may sound like a minor bug but the easiest way to defeat Yasuo in lane is to try to proc his passive before trading with him.

so tl;dr, As long as Yas is spaming his e he seems immune from aura damage effects.