Illaoi Ult is a problem
The problem is, she can feed and still do major damage.
In fact, teams often think because she fed and has no kills that shes not a threat, and then she ults a group and kills everyone.
This almost is like rewarding her for sucking in lane.
Sometimes I think Riot sits down at meetings to discuss their plan for making sure that the game is as annoying as can possibly be.