Passive: Umbra Blades
Nocturne's basic attack is periodically enhanced, dealing 120% AD physical damage to his target and surrounding enemies, and healing himself for 15 − 40 (based on level) (+ 15% AP) per enemy hit.

Basic attacks reduce Umbra Blades' cooldown by 1 second, increased to 2 seconds against enemy champions.

STATIC COOLDOWN: 10

Q: Duskbringer
Nocturne sends out a shadow blade in a line that leaves a dusk trail on its path, dealing physical damage to enemies it passes through and causing enemy champions hit to also leave a dusk trail behind their movement for 5 seconds.

While on the dusk trial, Nocturne is ghosted and gains bonus movement speed and bonus attack damage.

damage:
65 / 110 / 155 / 200 / 245 (+ 75% bonus AD)

movement speed:
15 / 20 / 25 / 30 / 35%

Bonus AD
20 / 30 / 40 / 50 / 60

W: Shroud of Darkness
PASSIVE: Nocturne empowers his blades, permanently gaining bonus attack speed.

ACTIVE: Nocturne gains a spell shield for 1.5 seconds.

If Nocturne blocks an ability, the passive bonus attack speed doubles for 5 seconds.

Bonus attack speed:
20 / 25 / 30 / 35 / 40%

COST: 50 MANA

COOLDOWN: 20 / 18 / 16 / 14 / 12

E: Unspeakable Horror

Passive: Nocturne gains 335 bonus movement speed when moving toward fleeing targets.

Active: Nocturne plants nightmares into his target's mind, dealing magic damage over 2 seconds and forming a tether between him and his target.

If the target does not break the tether by moving out of range, they are made to flee from Nocturne for a short duration while slowed by 90%.

Damage
80 / 125 / 170 / 215 / 260 (+ 100% AP)

Fear duration:
1.25 / 1.5 / 1.75 / 2 / 2.25

TARGET RANGE: 425

TETHER RADIUS: 465

COST: 60 / 65 / 70 / 75 / 80 mana

COOLDOWN: 15 / 14 / 13 / 12 / 11

Ultimate: Paranoia
First Active: After a brief delay, Nocturne applies nearsight to all enemy champions for 6 seconds.

Second Active: While Paranoia is active, Nocturne can reactivate it to dash unstoppably to the target enemy champion, dealing them physical damage

damage:
150 / 275 / 400 (+ 120% bonus AD)


TARGET RANGE: 2500 / 3250 / 4000

EFFECT RADIUS: Global

COST: 100 Mana

COOLDOWN: 150 / 125 / 100

While all magic can be dangerous and unpredictable, there are some forms or disciplines that even the most skilled mages and sorcerers will shun, and with good reason. For centuries, the practice of “shadow magic” was all but forbidden across Runeterra, for fear of reawakening the horrors it once unleashed upon the world.
The greatest of those horrors has a name, and its name is Nocturne.
Towards the end of the Rune Wars, desperate for victory, cabals of warrior-mages sought any advantage they could find over their foes. Although no record names the first of them to cast off their flesh and enter the spirit realm, it is known that they came to stalk one another not only on the battlefield, but in landscapes shaped by their own subconscious thoughts and emotions. Unconstrained by the laws of physical reality, they fought in ways that more mundane minds could scarcely comprehend, even conjuring subtle, etheric assassins to do their bidding. Shadow mages seemed particularly skilled at such things—and so it was, for a time, that they came to dominate the spirit realm, casting it into twilight.
The thoughts of mortals everywhere were touched by this darkness. It sapped their morale and infected their dreams, with nameless fears hounding them day and night, driving some to commit ever more horrendous acts against their own kin.
No one can say for certain whether all this suffering created Nocturne from nothing, or if it merely corrupted a lesser assassin-construct into something more willful and deadly, but the shadowy creature that resulted was one of insubstantial form and fathomless dread. Nocturne understood nothing of kindness, honor, or nobility—it was terror made manifest, with none of the restraint necessary to control itself.
This demonic creature howled within the spirit realm, and set upon those foolish, errant mages who had given it life, thrashing in desperation for an end to its own suffering. It was in pain, and that pain made it cruel, but it quickly acquired a taste for mortal fear. Time has little meaning in that other place, but Nocturne dragged out each and every pursuit for as long as possible, savoring the prey’s anguish before cutting their life’s silvery thread in an instant. Soon enough, there were none left who dared to enter Nocturne’s domain.
Would the outcome of the Rune Wars have been different if the demon had not played its part beyond the veil? It is difficult to say for certain, but afterwards, what little remained of the lore of shadow magic was hidden away, and its practice carried the sentence of death in many lands.
Trapped in the spirit realm, and with precious few intruders to sustain it, Nocturne began to starve. The only thing close to the delectable feasts of fear it had once tasted was when mortal minds unknowingly drifted through the ether in the hours of sleep. Drawn on currents of magic to where the two realms divide—and where peaceful dreams can easily become night terrors— Nocturne found a way to manifest itself into the waking world.
Existing now as a shade, eyes burning with cold light, Nocturne has become a sinister reflection of the most primal fears of the many peoples of Runeterra. From the bustling cities to the desolate plains, from the mightiest king to the lowliest peasant, the demon is drawn to any weakness of spirit it can twist into mortal terror, and everlasting darkness.

Duskblade of Draktharr Is definitely a core item on Nocturne as it will always proc when you Ult

Guinsoo's Rageblade gives you the AA stacking passive which Is very useful as nocturne relies on his autoattacks a lot

Blade of the Ruined King the attack speed, lifesteal, and on-hit passive all work well with nocturne's kit

Mainly the stats you want to go for when playing as Nocturne is Ad and attack speed, however there is an off-tank build which i have included the runes for, this focuses on AP and Tankiness. For that build you want to Max E first. You will want to ult into the middle of the might and E the biggest threat. Blade of the ruined king still is good due to the healing.

Hail of Blades
This is a rune that is more adept at deleting targets, rather than taking on bigger foes, you will suffer heavily if you are behind with this rune.

Lethal Tempo
The all-around best rune for nocturne. The attack speed kicks in about the same time as your fear, so once this hits them they should be dead. The only downside is the delay on the attack speed.

Aftershock
This rune is only good on off-tank nocturne. The extra tankiness and damage is welcome. Note that your only way of triggering this is your E, so if they flash or get out of the range you will be unable to proc it.

Passive:
this is your main sustain in lane. If you are anything less than full health you should walk into the minion wave and auto attack. This is also a very good ability for teamfights, as it deals AOE damage. Note that the heal scales with AP so if you buy something like Guinsoo's Rageblade you will increase the heal.

Q:
Your main poke and damage. The mana cost is very high, so you should only use it when you are sure you will hit the enemy champion. Note that the cooldown does not decrease with level. The dusk trail left by this ability increases your AD and MS, so it is useful as an escape or gap closer. This ability is almost useless as tank nocturne, except for keeping the tether of your E intact.

W:
This ability can save you from a gank if you use it right. The spell shield window is incredibly short, so you have to time it right. Remember that it has no cast time, so if you are able to cast abilities, you can cast this. It is easy to waste this ability if you think that something is going to hit you. Use this ability to block crucial CC engage abilities that junglers may use. Note that leveling up the ability increases the passive attack speed, so if you need attack speed you can level this instead of your Q or E

E:
This is your main CC and assassination tool. You want to use this as soon as you can use it on your target. This should be maxed second on normal nocturne, but first on tank nocturne. The damage scale's off of AP. It is your only way of triggering Aftershock so use it wisely.

R:
This is your main gap-closer and engage tool. When used correctly, it can foil an incoming gank, or secure an allied one. The Dash range increases with level, so the longer the game goes on, the farther away you can assassinate from. With tank nocturne you should ult to the highest threat so you can E them immediately.

This is what makes or breaks a nocturne player. You need to Learn timings and when to go in and when not to go in. Let me make this clear, Nocturne is a diver not an assassin. Wen he dives into battle he is IN the FIGHT. Nocturne has no escape, his ult requires a target to dash to, so you cant use it as an escape. Your Q's MS boost wont help you much. Your E only grants MS while moving towards a target. Other than that you should be fine

I hope you enjoyed my Nocturne guide. I Discovered nocturne in late 2017, and have loved him ever since. with this build, i recently got an S in a 13/6/6 game.
I hope you all share my love of nocturne and enjoyed my Nocturne guide.
Just remember to Embrace the darkness