This is my first League of Legends guide and its about my favorite champion Nocturne!
I might even do a youtube video that show how i play him.

Basicly what i've gone for is armorpen marks and quintss becaus it helps me allot early game. Then i have cd reduction blues that will lower the cd of the ulti and that is to me verry important.
Lastly i have 5 AS runes as before i want to have a realy good early game, then we have 4 crit runes but you can choose whatever you want there realy i just took crit in this build becaus i dont have so much crit.

The items im taking is normal to a jungling starting items 5 hp pots and a cloth armor for strong early game. then ill usually buy berserker's and a wriggles.
after that im going youmuu's its a great item in my opinion for Nocturne.
then i'll go abit tanky with guardian angel it will help you trust me! Many will ask me why i take a Trinity force and thats becaus as nocturne you constantly use your attacks and that will give you the sheen buff so thats allways good.
after that.. well you can go for anything that will increase your mobilty or damage.
But as you can see i usually go for a Bloodthirster and replacing wriggles with a bloodrazor.

This build works great in ranked in my opinion, i have not tried it in high elo ranked matches but it should work out just fine.

My suggestion is to keep farming no matter what try not to go into any big teambattle at the start or early game atleast not before you get you guardian angel.
Use your Q : Duskbringer to kill minions and towers. I usually get the blue buff just to keep spamming my abilities, if you cant get it its not a such big deal you just need to be more carefull not to use your abilities to much outside teamfights.

As my summoner spells i take exhaust and ignite but you can allso go for other spells, other combinations. this is just my personal opinion.

If you have any questions or suggestions leave a comment down below and i will answer your questions.