Pro:
Can kill from a mile away(just kidding anywhere when in range)
Kill quick
Damage output high

Cons:
Subject to CC/Disable
Squishy at early game
Picked on by range

Plz...try out the build before criticizing, no trolling plz.

This is my simple build for Nocturne, I don't know how people build him like, I've seen some crazy build for him, some build works some build don't. But my build here has landed me 15+ kills in each game, making the opponent surrender before you even get to their nexus. When you look at my build it's not that powerful or dazzling but if you look closely you might just understand why this build works for him.

This is my first build for Nocturne, not the best or the worst but it works for me. Now I choose Manumane as my first item. Reason is simple, your going to harass your lane with DuskBringer all day long. The more you use the skill, the more your mana goes up and the more your base damage is increase as well, so its a ++ to both mana issue and early Damage output.

3 x Greater Quintessence of Desolation = Armor Penetration 10(rounded up)
9 x Greater Mark of Desolation = Armor Penetration 15(rounded up)
9 x Greater Glyphs of Focus = Skill Cool Down 0.65% Flat
9 x Greater Seals of Regeneration = .11 Health Regen 5 sec / per lvl

Pretty Plain N Simple:
I choose 22/0/8

Reason this is for mainly rushing in and finishing your opponents.
Offensive
Whats Needed:
Deadliness - Needed - this helps makes quick work of your enemy.
Cripple - Needed - this helps slow your opponent and the added effect from exhaust.
Sorcery - Needed - this help reduce your skill cooldown + your runes cooldowns.
Archaic Knowledge - Needed - this helps penetrate those heavy magic resisters.
Sunder - Needed - this help penetrate those heave armor resisters.
Offensive Master - Needed - this help kill minion/neutral mobs faster (1 to 2 points depending on if your going with Ignite as one of your summoners spells).
Lethality - Needed - generate higher damage output to enemy.
Havoc - Needed - just an increase to your base damage.

Not Needed:
Plentyfull Bounty - not needed, your not jungling.
Archmage Savy - you're not ap build.
Burning Embers - Not needed (but if you choose to use it take 1 point from Offensive Mastery into it)
Brute Force - Not Needed - the added 3 points does not scale by lvl so its just a flat amount.
Rally - Not Needed - again you're not ap build.

Defensive:
None

Utility:
Whats Needed:
Good Hands - Needed - 1 point is good enough
Perserverance - Needed - allows you to generate hp/mp faster
Awareness - Needed - allows you to gain exp faster.

Pretty Simple, I chose Flash and Exhaust.

Combination:
Flash + Ignite
Exhaust + Ignite
Flash + Exhaust
Exhaust + Clairvoyance
Teleport + Ignite
Teleport + Exhuast
etc......

I go with every other, but try to make all yours skill evenly and grab your master skill priority first.

Starting Out:
Start out with a Makei Pendant and 2 Health Potion
Farm and try to get early kills.
Grab Saphire Crystal and Boots of Speed
If you have enough gold upgrade your Makei Pendant and Sapphire Crystal to Tears of the Goddess
Farm and try to get more kills.
Return to get your Long Sword and if possible upgrade to your Manumane.

Now its Time to save up for your bloodthrister: This Item Cost Alot so try not to die while saving up.....
First get your B.F.Sword
Next get your Vamperic Sceptor
Return and farm and try to kill
Return and upgrade to your Bloodthrister

Now its time to work on your Banshee Veil: why do i need it, simple it helps when your opponents are going to focus on you in that team fight.
Grab your Health Crystal and Mana Crystal
Farm again
Return and upgrade it to a Cataylst Protector
Farm again
Return and buy a Negatron Cloak
Farm again
Return and upgrade to your Banshee Veil

Repeat the process for your second bloodthrister:
First get your B.F.Sword
Next get your Vamperic Sceptor
Return and farm and try to kill
Return and upgrade to your Bloodthrister

Now onto your last item, this item will make your opponent wish the game has ended already:
Your Guardian angel:
Grab the Chain Vest
Farm again
Grab the Null Magic Mantle
Farm again
Upgrade straight to the Guardian Angel

This build rely on team work alot, so every time your team is in fight, watch for those low health enemy and when you see the opportunity is right, dash in with your ult and finish them.

Your DuskBringer skill is a great skill for team fight harassment, remember your not the type of champion to dash in and dish out alot of damage, your the kind of Champion that wait for the striking opportunity to kill your enemy.

In a 1 v 1 situation, you will dominate your enemy, the Banshee Veil will help alot with those who like to cc/disable you, it will make them use one of their skill to get rid of your Veil, that just allow you to survive more versus those nukers.

The Gaurdian angel is there to help you survive, when your enemy does kill you, you are revive and use your flash to flash out of danger, if your enemy arnt aware that you have flash.

In conclusion, this is a decent build, I yet to try this in a ranked game, but normal games I've been getting 15+ kills, also in advance AI games, I've been gaining 30+ kills, so plz try this build out and leave me a feed back for changes/improvements.

Remember to always constant farm, farming is key to your success.