This is a very cool analysis and quite honestly, i think it's completely on the mark. I talked to Xypherous about the context, (because I lacked the context of the thread) and I do happen to agree with him that creatures, especially if they're to be featured such as a champion is, have to be relatable. That's the largest challenge when designing a creature as a champion. You have to avoid something looking like either an NPC or a raid boss. You can certainly have aspects of the two, but you still need something to ground it.
I think that's why anthropomorphic animals such as Volibear, Nasus and Renekton work. They're humanoid but still have heavy animal features. Certain champions however sometimes fall into those monstrous areas without completely succeeding I feel. We encountered that challenge with Skarner, though I feel with Skarner we did a pretty good job. Still, overall I don't think he's as popular as a lot of other champions. I'd say creatures have a smaller audience than more humanoid champions, that's not to say that audience should be under-served, I just think it happens to be a small audience.
That said, there's no reason we should back down from making monstrous or creature champions, we just have to avoid the pitfalls of Omen. What this analysis has shown sums up exactly what I felt when working on him. He became a mishmash that didn't have a lot of identifiable components, and where he was identifiable, the features really weren't compelling enough, nor were they cohesive.
I think we can make a successful creature champion but usually it takes longer for the idea to cook, and a lot has to be figured out as opposed to a more human or familiar archetype which can lean on immediate relatability. Creatures are challenging, but all good things come from challenges!
Ysereh: L = 9a