Hello this is my Nocturne build that is pretty good to get kills and support ur team with. I have also made a video with this build. Im not that good at making guides, but i will try. Play Video

Early Game: Go offensive, but dont use too much mana to dmg Garen, Warwick, Nasus and Nunu they can get on full hp quickly again.
Mid Game: U shall still go offensive but be careful cuz u will be focused alot in this periode.
Late Game: This is where the teams wont surrender so now u need to get Nashor/Baron and get in a teamfight kill them all and then finish the game.

Is a pretty good start item, because you lose fast hp and it is great to go offensiv with.Is good because u need much speed and attack speed + it is a good crit item when u got infinity edge.Maybe ur thinking why this item? Because all your spells is minimum 10 sec cooldown, and its annoying to wait that much time. It give good dmg too + i like this item because it cost 1337.

I think u know why i recommend the other items.

Is a good spell to gank with, and follow spell. It can be used many was, as a escape to get movement speeed with, making alot of dmg with, chasing, and it has a great team work with nidalees spear.Has a great team work with stun champions, because u can then stun them twice.This is one of my favorite spells, it is good at supporting/blocking spells for ur team with. Like i have saved many champions with this because of caitlyn's ulti you can just run into and block it, the same with blitch grapple hand.This is a good chasing spell if they will get away + it will be good if u kill one champion and the team cant see you.

Desolation makes a good armor penetration because i just hate all the tanks with much armor in the beginning the same withGreater DesolationNocturne use alot of mana so theese runes is very good to regain mana.+is the 10 dmg runes i use they make very good dmg to begin with, so i would recommend theese strenght runes.

I take 21-0-9 because it is the best way to get. I jungle alot with Nocturne to get the buffs, but if u want
21-9-0 then u can do that cuz u want take that much dmg.