You should elaborate more about what you have in mind because those wiki links are too big to read and look irrelevant.

But I am not sure why do you mention buddhism as origin of guro if more or less every fairytale I read in my childhood was pretty much a guros story very often even happy guro style where it doesn't even harm anyone for real.

also many cartoons made more than 20 years are guro in essence just rather than killing lolis they shoot talking ducks and decapitate cats. just think about that poor coyote who was trying to catch roadrunner :)

More food for thought woud be why guro disappeared from all mainstream media? but at the same time amount of violence on the streets and school shootings increased greatly.