Azir needs his knock up back.

I actually agree with you, but I think you're going to need a bit better of a reason than that.

Here, I'll try to help. Why would anyone use his E in its current form? Repositioning, escape, passing terrain, ... oh yeah and a teeny tiny shield?

Yeah, the first three are great because they all involve mobility, but for the most part they are used to evade. Sometimes people try the W Q E R combo to catch someone out but that is a very dangerous move because lots of champions can just destroy you if you don't do it just right.

Otherwise nobody uses E to gain the shield because it's weak. I did it on accident the other day and was confused where the shield even came from. So if I could change your request a little, I would ask for the knock-up back OR a stronger shield. Perhaps one that scales on something that people actually build on him like AP, Mana, CDR, maybe give it some sort of mobility mechanic where it is stronger if you have moved x units, or if you passed through a non-champion prior, or lets duration extend from attacks, ... something please.