[@KOgaming] This is a difficult one. I'd like to say an original setting akin to multiverse since there will be various inspirations coming from different sources. 

As for the power-ups, they'll both be gained and given. Power-ups can occurs as instant or gradual as needed; it really depends on what your character does. 

An example would be Character A. Character A enjoys punching and that is his move of choice. He loves it so much that even when it doesn't make sense, he'd still turn to his fists. Him receiving some sort of blessing from a martial-art based diety wouldn't be that surprising.

[@Masaki Haruna] As tempting as that sounds, I'm currently watching my figure. We men have to be cautious too, you know.