Daimajin’s design was inspired by prehistoric Haniwa figures, like this one on the left from Gunma prefecture.
I’m fascinated by the notion that Majin is a spirit that actually predates Japanese history. The movies take place during the Edo period, but Majin has been around since time immemorial.
The statue on the island in the second movie has a Shinto style shrine around it, but that seems to have been constructed after its discovery. In the third movie, the mountain that statue resides on is forbidden to visitors. The spirit that animates the statues is more ancient.
@Htop_Gunder I think this thread is relevant to your interests