Is there anything that makes Nocturne outright unviable in lane?
As in, trollpick-unviable. At the moment I mostly play Normals and probably wouldn't be trying this in Ranked unless it turned out to work really well for certain matchups.
I've become fairly experienced with Nocturne in the jungle; know his kit in and out, know how to build him strategically. An idea I've been wanting to try out recently is Nocturne in mid or possibly top lane; AD assassin for mid (maybe throw in a strong amount of lifesteal), and split-pushing bruiser for top.
It is possible to find guides and videos on lane Nocturne, and I think I've seen one or two of those featured Ranked matches you can spectate in which someone brought him top lane. So I know there are at least some people out there who try it. (This would be excluding the niche case of Lane Nocturne being a strong counterpick to Twisted Fate)
I am aware that the two main arguments against the idea are his passive, and his mana limitations. That said, I'd think if you were careful about your autos and positioning you could avoid having the passive hit too many minions. I would also think he has good trading potential thanks to his spellshield. And if your jungler lets you have most of the blue buffs, that would circumvent his innate mana problems.
Is there anyone who still pulls this off?