Explanation of Powers in Mangas

I don't understand some of the shit when authors describe how the power was generated, why it worked, in what conditions it wouldn't work, why it was an exception, how the protagonist's 7th blood cell helped accelerate it, etc etc in the manga, or even in the anime. I'm just like 'Yeah yeah, yada yada, kaboom' , like the MC swung his sword and boom. They pushed him too hard, kaboom. Don't slime me for this