Riot's skin design team, Is it hard to think of a skin for Nocturne?

When I look at skin ideas for Nocturne, I don't really see people creating anything fascinating as they do with typical champions like

Like its easy to illustrate what kind of skin you would like for them but when it comes to Nocturne, I for some reason feel like he's rather difficult.

It's almost like every champion has it's own difficulty level in thinking of ideas for skins.

Well when you do come up with an idea for Nocturne, I hope it's something menacing and dark like his base. Don't let the fear/horror lovers down! (: