[GAMEPLAY] Cassiopeia's Miasma has no visual effect on the map (in ARAM).
I'd say this is easy to replicate, but getting a champ you want on ARAM is impossible. However, the other day, I ran into a Cassiopeia with the Mythic skin, and her Miasma had absolutely no visual effect on the ground when it was used. It was simply casted, and then you wouldn't know it was there until you walked through it and were slowed+taking damage.
For clarity, this wasn't in a bush or anywhere you have no sight like fog of war. It just was 100% of the time invisible. I specify the Mythic skin, because I played against a Cassiopeia without it, and the Miasma poison foggy crap on the ground was plenty visible. Also, I don't have the Mythic skin so I haven't been able to test it on a Summoner's Rift map. Not sure if its directly associated with the skin or just was already hotfixed, but if its not, it should definitely be looked into.