As nocturne, He is frail pre-six because he has no way to gap close and get close to his enemies. He should powerfarm as much as possible.

His strength skyrockets post-six as he can gank the enemy reliably. He should focus on lanes where his allies have some form of hard CC or where the enemy is too pushed up.

The first item component will increase his clear speeds and let him deal a lot of damage in a very brief amount of time. This is quite helpful when ganking.         As nocturne, It is fragile before six because it has no way to get closer and closer to its enemies. It should powerfarm as much as possible. Its force skyrockets after six that it can win the enemy reliably. It should focus on the tracks where its allies have some form of hard CC or where the enemy is too pushed up.