Well this is my Nocturne build i hope you like it and try it :) Please try it first before you vote down or up. cheers :P the health and that is all wrong for some reason so just try it out and have a look :P
Before Nocturne, people believed that dreams were figments of their imagination, meaningless images that flashed through the mind when one slept. This belief was put to the test when a rash of sleep-related incidents started afflicting summoners of the League. Some would wake up screaming, terrified and beyond consolation. Some could not fall asleep, slowly going mad as the nights ticked by. Some simply never woke up. Physicians were baffled until a Field Architect happened to pass out next to a nexus on Twisted Treeline. Witnesses said he cried out once and then stopped breathing. Immediately after, magical energy arced out from the nexus, and Nocturne appeared.

Nocturne did not take his introduction to this world kindly. He slaughtered everything he could find before summoners were able to magically confine him. After a period of intense study, League experts divined that Nocturne hunted summoners in their sleep, attacking them in a place where their magic was useless. This seemed to be his only purpose. The families of the victims demanded justice, but League officials were concerned that death might only return Nocturne to the place from which he came. They bound him to a nexus fragment, trapping him in the physical world. As punishment for his crimes, they allowed summoners to call upon Nocturne in the League matches, bending his will to the summoners he hates and creating his own personal nightmare. League scholars don't know whether he truly came from the plane of dreams, or whether there are any more like him. Some theorize that the summoning act affected summoners' subconscious minds, luring Nocturne to them in their sleep. Perhaps the most disturbing theory is that Nocturne is a person's nightmare come to life. If this is true, they wonder, who is the dreamer?

I get desolation marks for the armour pen which is helpful for taking down enemies.
I also use 4 seals of replenishment for the mana regen and 5 seal's of vitality for the health per level. because this helps alot because the more mana you have the more time you can stay and fight and also the reason i use seal of vitality is because it is useful to have a bit of health.
I get glyph of focus because it reduces the cooldown of your moves which is helpful for doing damage quicker to enemies.

I use 21,0,9. I have 21 in offence because i want to boost my damage output and health. and i have 9 in utility because it helps with your mana and death time so you can do more moves and get back to battles quicker.

I get these items because there really good and helpful and i added yoummum's gohstblade because when you get late game you dont really need doran's shield so you can sell it and get yoummum's gohstbalde for more output.

i use this skill sequence because i think it is very good to max out 'E' first because of the Fear and you obviously get your ulti when ever you can. then you max out your 'Q' and then your 'W'

I use flash so I can get away from battles easily if my team dies and I also use ignite because when I don't want to tower dive and there on low HP I just use ignite and that should kill them unless they heal.

so make sure you actually try this build before you say its **** thanks .