Back in the day when I first thought about a Cass rework...
I imagined they would rework her E actually. She seems to be about zone control and poisoning enemies, and her E always felt like an odd addition to her kit. I find it really odd that they decided to just focus on the E, when my friend that used to play League said that he hated Cass's E, and he really only ever played her. Here we have this zone control DoT bully champion with a single target Marksman-esque DPS ability... What?
I always thought her Miasma was the most iconic part of her kit. "You cant fight in this part of the battlefield now bitch"