Vel'Koz passive on other Champions BUG

Unfortunately I was unable to record the gameplay, but I will try and replicate and record it shortly.

Here's a basic summary of the bug: In the past, I recall that whenever Vel'Koz applied a stack of his passive to you, you would see not only the little icon above your abilities, but his passive in-game on top of your champion. (Maybe I remember incorrectly, feel free to correct me). This past game I played, I failed to pay attention to that little icon above my abilities, so every time I would fight Vel and fail to avoid some of his abilities, suddenly there would be a huge drop in my health due to that passive. I understand how the passive works, but I just didn't realize I had 2 or even 3 stacks on me at the time.

If it helps for others to replicate, I was playing Morgana mid with Ignite and Flash, and was laning against Vel'Koz with Barrier Flash.