Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This build plays on Nocturnes ability to life steal. By giving him attack damage, extra life steal and attack speed, he can 1v1 almost any champ and can last a lot longer in team fights if he keeps his cool.
I am using these runes to give him a strong set of legs to stand on. The boost to defense allows him to stay and harass the enemy a lot longer in the early game and is harder to kill from ganks. The high armor pen allows him to gain as much off the life steal as possible.
I choose these items for there usefulness. Not only do you need life steal and damage, but without the attack speed the enemy will be able to kill you to fast. As the fight goes on, and you get more and more feed, sell the lantern and buy another Bloodthirstier. That will put more kills under your belt.
Using the exhaust and horror in a team fight, you can target and handy cap more than one champion at a time, making it hard to fight as a team. You can also us them in tandem on the same champion, Using horror first and then exhaust you can lock them down for quite a long time. If you use it in the other direction, by the time exhaust runs out, horror will take effect. Another long time for them to do nothing but get raped.
My average kill/deaths is about 12/3. I have much better games. Play this guy smart and this build can go a long way. Be sure the vote, would like to see some feedback, being this is my first attempt and writing down my builds.