For me, I just love the contrasting black and whites using ink and paint and seeing how the two colours compliment each other, especially with lots of use of the white paint splatter technique.
Also, I thought you might enjoy this other video drawing some kind of variation of a Demon skull in death metal style. Also in timelapse.
You might also want to check out How to draw a Death Metal Zombie Head for some further ideas in drawing in this horror style.