Along with Yasuo's windwall and Zoe's W.
This ability has LITERALLY zero counterplay, all you can do is wait for Akali to show herself or try to run away.
It covers a big ass radius, has its duration EXTENDED every time Akali enters stealth and provides stealth AND untargetability for a very long time if we consider what kind of game League is. And let's not forget that if Akali attacks while into it, after 0.5s she's already stealthed and you have such a little window to counter attack her that it's like there's none.
Really, who the fuck thought that an ability like that was okay for this game, especially on an assassin? Akali is so fucking hard to kill after 6 because she can just press W and hey you can't do shit about her except trying to hit skillshots like you're blind.
Removing its duration extension would be a step in the right direction.