[GAMEPLAY] Veigar E disapears prematurly if Veigar dies shortly after casting it.

I used Veigar E (Event Horizon), the ability visually showed up but wasn't yet at the point of stunning anyone, I died before the ability was at the point of being able to stun anyone I think, which probably caused the ability to disappear from the field prematurely. That's what it looked like to me. It's supposed to stay on the field for a little bit but this one didn't.

EDIT: I was playing ARAM at the time, in case that matters.