Cass gets New CC - Grounded -

W - "Cassiopeia releases several clouds of poison, lightly damaging and slowing any enemy that happens to pass through them. Enemies affected by this poison are Grounded, losing the ability to use Movement abilities."

Riot Repertoir confirmed in this post.

Anyways. I wrote a year ago that Riot should implement a new CC called Grounded and I defined it. It's happening! :D