I think that necromancy is actually a very creative thing. Whether it's religion or witchcraft, they are all created out of nothing by the ancients, and this is a unique power system. In Japanese cartoons, we always see many things that we used to denounce as superstition, such as Shinto beliefs, folk superstitions, god-invoking fairs, and more commonly, such as spirit mediumship (summoning), necromancy, and corpse-driving techniques, etc.