Are you questioning yourself why they like it? Why they want it? Why they do it? For example the tree of adam of one piece, devil fruit, pirates like blackbeard, yata miror on naruto, izanagi,izanami. Bleach, hxh, full metal alchemist, all this manga was influence by real world stories, myths, legends, real people but why they like to do it?
The answer:
All this manga authors was usually took the course of fine arts or above that...
In fine arts it so easily to get influence by anything, if you see a stone for example, you can make it something a villain who breaths fire, with laser beams while growling with anger, thats just a example how they sometimes see it.
Tradition is one of the answer, many countries have so many traditions thaosand of thaosands of tradition, in their mind, they want it to be alive...
theres a lot but theres one thing that connects manga authors as one! and That is "Change"
The answer:
All this manga authors was usually took the course of fine arts or above that...
In fine arts it so easily to get influence by anything, if you see a stone for example, you can make it something a villain who breaths fire, with laser beams while growling with anger, thats just a example how they sometimes see it.
Tradition is one of the answer, many countries have so many traditions thaosand of thaosands of tradition, in their mind, they want it to be alive...
theres a lot but theres one thing that connects manga authors as one! and That is "Change"