For Me Ornn is a Good Champion depends on the Player who uses him,
he can also be a good setter/tank if he was used correctly I use Ornn Top/Support Due to his CC abilities also for his passive that allows his team to Upgrade benefits all of your allies like Upgraded IE,Solari,Redemption etc.,
you can turn the tides of battle using his
R, then W => Q => E for a Massive CC, but he is not a good damager, but he is good on teamfights like 3v3 - 5v5 clashes
overall he's a good champ if used correctly.