Not sure if this is something that's being tested, but at the moment Akali's shroud has a very cartoon like overlay on it. It has a thick red outline around it. This occurs with Default Akali and Blood Moon, haven't tested others yet.
The third image is the Akali VFX "Bug", second image are my current settings.
The first image is what is currently created as a screenshot in fullscreen when F12 is pressed.