Nerf Akali and Irelia the same way you nerfed Zoe

So why would we nerf Akali?

You should try to play her. Most players brush off the benefits of actually being in the skin of their nemesis. It's funny how it's expected from Akali players to train hard to be good when in the meanwhile people want to be able to play against without much practice. It goes both ways, the champion is quite difficult to handle, you'll get a clear view of her struggles when playing her directly.

[By "difficult to handle", I mean there's a world between a good and a casual Akali; doesn't mean a beginner can't plow down opponents lacking knowledge, making him look like he knows what he's doing]

Basically, if enemy Akali can use her smoke to casually farm and trade, you're not applying enough pressure. Think of her Q as an ammo system: she can use it a couple times in a row but if she does, she's up for 10 seconds of Cd. The most important thing is: you MUST position in a way Akali can't proc her passive without using either W or E. If she can walk up to you and Q you directly, you'll take a lot of unnecessary damage. Akali doesn't see you as a champion, not even as a prey, but as a mobile energy restoration station: the whole purpose of the champion is to abuse her energy mechanics to break standard limitations (and if your opponent dies from giving energy too often, that's a nice addition). Every spell she's using not restoring her energy (smoke while full energy, or not procing/using her passive) grounds her to basic, almost low level of threat for a few seconds.

That said, I think she could be a tiny bit nerfed, but not the Obscured effect nor the duration, she needs that to combo properly. But I find her movespeed while in smoke too deceiving, 10-20% bonus should be enough, 20-40% makes her fly around you like distance is nothing and flat mobility like that is a bit hard to counter since she can use that speed to dodge effectively most non-targeted spells.