Meralman
Just because it's not cliche doesn't mean it's better. He trained for years and now he's finally in a real battle giving it his all, he's practically fulfilled the requirements to awaken Haki It's like he's a flawed hybrid of a real-life human and a human where piece , the "rules of the world" only partially apply to him while the rest of the world has access to advantages. I understand you want to make the story more serious and realistic (As realistic as being reincarnated in one piece) but it seems like you're Nerfing him for the sake of the story being unique. One Piece has two "systems of power" one of which we follow from the first episode but you've already made the preparations and had the opportunity to integrate it into the story but chose not to. It's your job you choose how the plot goes and I intend to keep reading. Small observation: Broly started out very op (and I know it could be even more so I'm not complaining) while Fred, no matter how hard he tries can't reach one of the essential sources of power to survive/evolve in this world (unless you have some special bloodline or has been modified before birth etc). (I used Google translate sorry for any mistakes)
Meralman:In my opinion the Akuma No Mi's are products derived of advanced Haki technology in combination with DNA manipulation That's why the Haki nullify and affect's them