Invisible ultimates

In some of my games lately I have been on the receiving end of an invisible MF and Vel'Koz ult. MF was in midlane top brush ulting into lane in a fight. Didn't see her obviously, but didn't see the ult animation either and dies from what I thought was full health to a single aa from someone. Only knew it was her ult form the death thingy in the top that showed I took 1800 ult damage. Same story with the Vel ult, didn't see him from fog, but neither his ult and it killed me, because Vel'koz. Is this a thing where animations are invisible if thrown from fog and I never noticed it before, or is it a bug?
Report as:
Offensive Spam Harassment Incorrect Board