Akali has absurdly high ban/pick rate.
I'm not saying she is insanely overpowered, but her kit inherently offers minimal outplay. With a 85% ban/pickrate in diamond+, clearly no one want to play against her, as she is insanely unfun and has 0 room for counterplay in the hands of a competent player. Her first item powerspike takes a lot of players by surprise, her shroud needs tweaks to make it counterplayable, and the amount of healing from her q + gunblade is absurdly high. In fact just facing off against an akali is extremely demoralizing, regardless of how behind she is once she picks up one or two kills from your teammates she will start to do serious damage and carry fights.
To fix this, I propose that if an akali was to be displaced in her shroud (Ie. a knockup, a blitz pull, etc.) she should be visible for a brief duration before returning to shroud. The old akali had this mechanism, and it was a good way to punish her for mistakes. By doing this it would allow room for counterplay to shut her down, instead of having to wait for the shroud to completely disappear while the enemy team slaps you around. In addition, i think a percentage decrease on her q heal stack with other items would be great. Maybe a 10% reduction or so in healing when stacking her q and gunbladepassive would help those laning against her, meaning she would have to rely more on skill expression than "Oh i fucked up so ill drop a q heal for 300 and then shroud away."