Here's my finished Oni Boulder based on Glenn van Driel's excellent concept art! (https://www.artstation.com/artwork/qAAZNn) Check out the full challenge thread here:
I wanted the light set up to be something reminiscent of a group of travelers in the untamed forests of Japan stumbling upon a forgotten relic stonework. Casting torchlight upon the stony facade, they'd see the weathered charms and fading paint, along with strange crevices carved into its surface by unknown sharp things. Exposed to the elements, moss and mildew claim their territory along the wet expanses of the Oni Boulder. The travelers see this and make haste; wary of what the Boulder's purpose might be.