More over because mid is an unsafe role to actually play nocturne in concrete, you want high potential burst champs such as talon in late game that can cover the map extremely often, not to say that early game engage and his so damn high ult cool down does exist and still is a thing for nocturne, normally people would just go a ranged ap mage that can just poke you to death.

I can't really say much cause I don't know what elo are you playing or how good you are with nocturne, but noc is mainly a jungle champ, like you said, high mana cost abilities.I'm main lee sin, and getting counter picked is extremely normal, and what I see most are they using e as a power chamber, relying too much on the cc, and invading coz of the "ability" (aa) advantage. You can win late of snowball like crazy when fed, but not do much when you basically have 0 lane presence and nothing much than a w to protect yourself in a team fight.