Here is my guide to Nocturne. When Nocturne was released I already had some items in mind and had successful games as him. When I turned to jungle Nocturne my items changed for the better and improved my game play. In this guide I will show you which items I buy with Nocturne and how to use him both in lane and as a jungler.

PROS

Paranoia makes a great ganker.
Duskbringer with theses items gives him some insane attack damage.
Duskbringer can show you where an invisible enemy is if you hit him with it.

CONS

Suffers against high damage casters, e.g. Malzahar and Ryze.
Suffers against high armor tanks, e.g. Rammus with Thornmail.

Umbra Blades: Every 10 seconds, Nocturne's next attack strikes surrounding enemies for 120% of his physical damage and heals himself for 15 / 20 / 25 per target hit. Nocturne's basic attacks reduce this cooldown by 1 second.

Duskbringer: Nocturne throws a shadow blade which deals damage, leaves a Dusk Trail, and causes champions who are hit to also leave a Dusk Trail for 5 seconds. While on the trail, Nocturne ignores unit collision and has increased Movement Speed and Attack Damage.
Cost: 60 / 65 / 70 / 75 / 80 mana.
Physical Damage: 60 / 110 / 160 / 210 / 260 (+0.75 per bonus attack damage).
Movement Speed Bonus: 15 / 20 / 25 / 30 / 35 %.
Attack Damage Bonus: 20 / 30 / 40 / 50 / 60 .

Shroud of Darkness: (Passive): Nocturne empowers his blades, passively gaining attack speed.
(Active): Nocturne creates a magical barrier for 2 seconds which blocks the next enemy spell. If an ability is blocked by the shield, his passive attack speed is doubled for 5 seconds.
Cooldown: 20 / 18 / 16 / 14 / 12 seconds.
Passive Attack Speed Bonus: 20 / 25 / 30 / 35 / 40 %.

Unspeakable Horror: (Active): Nocturne plants a nightmare into his target's mind, dealing magic damage over 2 seconds and fearing the target if they do not get out of 600 range of him for the full duration.
Cost: 60 / 65 / 70 / 75 / 80 mana.
Cooldown: 15 / 14 / 13 / 12 / 11 seconds.
Total Magic Damage: 50 / 100 / 150 / 200 / 250 (+1.0 per ability power).

Fear Duration: 1 / 1.25 / 1.5 / 1.75 / 2 second(s).

Paranoia: Nocturne reduces the sight radius of all enemy champions and removes their ally vision for 4 seconds, this includes champions, minions, wards and towers. He can then launch himself at a enemy champion with a large range. Deals physical damage on arrival.
Cooldown: 160 / 130 / 100 seconds.
Physical Damage: 150 / 300 / 450 (+1.2 per bonus attack damage).
Range: 2500 / 3250 / 4000 .

One thing you may have noticed about the runes I chose is that on the Laning build I chose to have Greater Glyph of Celerity instead of Greater Glyph of Focus because as a Laner you dont really need much CDR early game but late game it is a nice bonus whereas as a Jungler you will want nice CDR early game to make sure that you can get that Duskbringer back as soon as possible for the damage boost.

Greater Mark of DesolationGreater Mark of Desolation - Gives your attacks a bit of armor pen to get through their armor.
Greater Seal of Alacrity - Another bit of bonus attack speed for him, nice for early game jungling.
Greater Glyph of Focus OR Greater Glyph of Celerity [EXPLAINED ABOVE]
Greater Quintessence of Fortitude - In my opinion this is GREATLY important because without this I'm pretty sure you WILL die the way I jungle.

I don't believe I have to write much in this chapter because it is pretty much self-explanatory.
I decided to go 21/0/9 because he needs the Spacial Accuracyfor teleport (Obviously if you decide to not take teleport you should NOT take this mastery), Awareness for the Jungling or just to get ahead in lane, Utility Mastery to make that jungle buff last a little longer.

MUST HAVE SPELL FOR JUNGLING

Smite

Preferred Summoner Spells

Teleport
Exhaust
Ignite

So-So Spells

Flash
Ghost
Heal

DO NOT TAKE THESE SPELLS

Revive.... Are you joking?
Fortify Leave it to the tanks.
Rally....Pointless.
Clarity His spells don't nom away his mana.
CleanseCC should not really worry you much, I doubt you would be targeted if you have squishies.
Clairvoyance Not needed.

LANING ITEMS:

Start off with Boots of Speed, Health Potion x2 and mana potion.. On your first back try and get Berserker's Greaves. Then get a Zeal. After the Zeal you want to get a Vampiric Scepter before you finish the Phantom Dancer. After you get the Phantom Dancer you should finish The Bloodthirster that you started with the earlier Vampiric Scepter. Start building the Trinity Force starting with the Phage, Zeal and finally the Sheen. Once that is complete head for The Black Cleaver. For the last item I suggest either The Frozen Mallet OR The Banshee's Veil. If the enemy team has a caster such as Karthus I suggest getting The Banshee's Veil before Trinity Force but if you feel like more health would cut it go for The Frozen Mallet.

Stark's Fervor - Nice item especially in team fights. Works well with the Black Cleaver to remove their armor. Definitely a good item if you are against some armored tanks.
Infinity Edge - Some nice attack damage and critical strike along with your Phantom Dancer and Trinity Force. Also it buffs those crits up to 250%. Nice item.
Last Whisper - Great against armored tanks to get your hits through with that 40% ArP. Also some decent attack damage.

Berserker's Greaves - Move speed 2, Extra Attack Speed, It is a nice item for him but if you feel that the enemy team has a bit too much CC definitely go for the Mercury's Treads.
Phantom Dancer - Extra move speed, attack speed and Critical Chance, extremely nice item.
The Bloodthirster - This item is amazing when stacked. It has the most damage in the game and 25% lifesteal so if you are low after a fight you can just heal up on minions.
Trinity Force - Pretty much EVERYTHING is in this. Move speed, Crit chance, Attack speed, Mana, Ability Power, Health, Attack Damage and a slow. Now THAT is nice.
The Black Cleaver - More attack speed which should bring it to around 2.000 I THINK. Extra attack damage and then the passive that removes 15 armor with each hit and can stack up to 3 times. That is just great for ripping people down.
The Banshee's Veil - Health, Mana and MR. Great against a caster team and it can block 1 negative spell every 45 seconds. Very nice item.
The Frozen Mallet - Health and attack damage. It also adds on to the slow of the Trinity Force so red buff is no longer a must have.
Madred's Bloodrazor - Helps destroying creeps like Dragon and Baron much easier and also destroys tanks along with The Black Cleaver. It also boosts that Attack speed.

Jungling can be a bit dodgy for Nocturne but he is certainly capable of doing so. This is my jungle run.

1.Buy Cloth Armor and Health potions x5. Head out to the Ancient Golem. Unlock Duskbringer.
2.Lay down Duskbringer as much as possible. Make sure to pop a health potion at the start and smite near the end. ( Greater Quintessences of Fortitude are needed).
3.Next unlock Shroud of Darkness for the bonus attack speed and move on to wolves. Pop a health potion and kill them.
4.Then move onto Wraiths. Pop another health potion and you lay down Duskbringer and take them all out starting with the large one.
5.Move on to the Golems. Lay down Duskbringer and smite the one on more health.
6.Port back and repeat steps 3-5 until you can get Madred's Razors.
7. Then head out to the Lizard Elder. He should be easy kill. Lay down Duskbringer and smite when hes on low health.
8. Keep jungling until Smite and Ancient Golem is back and kill it.
9. Of course Gank when possible.