I believe that Nocturne is Zed in the future when he is consumed by the shadows. One example for why I believe this is that Nocturne and Zed both basically have the same quote. Watch the video (press the link) for more information. This really is an interesting theory.
is the same as 
?????
I doubt it. Nocturne is a living nightmare with powers over darkness,while Zed is a ninja with shadow powers. Shadows =/=Darkness.
Zeds quotes simply reference his lore(what he can't undo is the destrcution of the kinkou,he embraces the shadows since he embraced the shadow techniques),the similarities to nocturnes are simply a coincidence.
Aside from that they both use blades which explains some of the similarities.
Nocturne being born from Shens nightmare sounds a bit more likely,but it'd be a bit weird since shen is supposed to be rather emotionless(he saw his own father being tortured in front of him),so it'd be out of place for him of all people to have such a nightmare.
watch the video guys
thank you for answering
i dont really care aboiut the bad english
