Wait a second, Ornn sounds like he should go botlane
I know what you're thinking, "oh you're an idiot", or "wow stfu noob l2p the game adcs go bot"(you're obviously not thinking that), but hear me out. Ornn's kit to me screams like it can replace the ADC in the bot lane.
His kit synergizes with cc. What champions have great CC? Supports, junglers, and top laners. If you put Ornn in any of these lanes, you technically reduce the effectiveness of his cc extension.
What about laning? Well, ADCs are generally weak in lane, and supports are much stronger in lane. They can harass, they can shield, they can trade, and they generally help your fellow bot laner get through the laning phase. So the fact that Ornn's melee won't be too big of an issue. This is combined with Ornn's shield, gap closer, and knockup which will be useful against the terrain in bot lane.
But what about late game? ADC's are needed late game, right? Not necessarily. Ornn's passive item upgrades would be great for the late game, and could be great for champions who already scale in other lanes. Also, since you're already going to be a tanky member on your team, it opens up room for squishier top laners who also have dps and cc. Think champions like jax, riven, and irelia.
Now, I could also be full of shit and he's complete garbage in the bot lane, but I think he's going to be the best possible melee champ to replace an ADC. I know i'm going to try it out.