The one nerf exhaust really needs

Remove its ability to be cast while stunned, taunted etc. So ridiculous you can see pro players abusing this all the time, where youd expect immobile mids to pick cleanse vs the likes of cassiopeia, they take exhaust because if they get hit by the ultimate they can simply negate most of the damage and either turn the fight around or disengage.This is also problematic in teamfights where ccd champions should never be able to render an enemy who successfully ccd them useless for several seconds.