Ornn and Why He's the Demi-God of Losing Games.
Ornn is a great champ - I've played him a lot and he is ton of fun to play - but he doesn't have a clear identity.
Top lane? Not enough kill pressure. Not a single match-up where he is dominant.
Jungle? Terrible clear speeds, poor itemization, and lack of reliable ganks.
Support? CC is unreliable and requires setup, no supportive spells for Marksmen. Kite-able.
He's a mess. We all know it and the biggest mistake that might be made is to keep buffing his W. I am glad that the %Max health scaling damage change was not made, because honestly that was a band-aid fix to a bursting pipe of a champion.
So here's how you fix him: Give him a clear identity. Is he a top laner? Give him more skirmish power.
Jungle? Make his gank's more reliable.
Support? Add some sort of supportive functionality. Maybe he can allow his Marksman to shop in lane as well (obviously this would all be gated for balance with a CD or what not)
But whatever you do, please do not shove more and more things into his W, it is ridiculous enough already.
tldr: Ornn is good at a lot, but great at nothing.