>>76829656unless you are VERY smart and concious of what you are doing, i think keeping everything vague bur logical is how you should do stuff.
Introducing hard laws/hard characters like say Gildarts from fairy tail just have you sweating and writing around them otherwise they solve any encounter.
Also i say logic because HxH stretches the logic of what an ability is to stupid levels and while some people will clap and go "OMG RUBBER NEN SO KINO" i just cringe into nonexistance when you go go UMMM ACKSHUALLY.
I enjoy worlds like DBZ or DMC where the scale is very set in "lets make something cool" and less in numbers (yes, i say dbz because it abandoned numbers a long time ago)