An idea on Cassiopeia
https://i.gyazo.com/78a3b6a3ec4cce2989005e642f34e018.png
Since the CD of her E is 0,75s it could be a viable toggle ability What if you can toggle her E?
How it could work: Whenever her CD is down she can use toggled E for the next auto attack To keep the normal casting possible you can toggle/untoggle her E by self-casting it