〜もなんともない

もなんともない flatly denies a feeling or quality: こんな映画、怖くもなんともない, "this film isn't scary in the slightest".

It follows an い-adjective in its く form plus も (怖くも, 痛くも, 羨ましくも), or a な-adjective or noun with でも (平気でも, 好きでも). The tone is dismissive, sometimes defiant or a little bit of bravado, so it's common in conversation and manga.

なんともない on its own means "it's nothing, I'm fine": けがはなんともない. Plain 〜くもない is milder and just means "not X, either". Because it sounds so dismissive, avoid it in polite conversation, where 全然〜ない or あまり〜ない is safer.