Why are there never original holidays in isekai if it's another world?
I was thinking while writing for a comic I want to make (it's not isekai, but it is fantasy) and I thought about how they always end up celebrating Christmas and things like that, so I thought about creating new festivities. For example (the following is the idea I want to be criticized):
A pair of villages with half-orcs and other races have a celebration. Every 3 years they make their children fight each other because of an ancient legend about two gods who fought to decide how to feed their inhabitants. One wanted to be recognized for the quality of his agricultural fields, the other wanted to hunt and raise animals with the help of beasts, so they fought to the death. Nobody knows which brother won, because the legend says they were incapable of killing each other, not because of weakness, but because of fraternity.
So the villages make their children fight with wooden weapons, and the winning village would be the one that prioritizes its respective field of work (agriculture or livestock) for the next three years, a celebration that has been passed from generation to generation.
A simple and entertaining celebration, something realistic in a way instead of always celebrating the same dates as if the world they are in had no culture of its own.