Now I love astro boy and would never wish him dead! However skulls are cool and anyone who read the orginal manga would find more than a few episodes where astro wanted to be more human, so I’ve just taken that idea and sprinted with it down the road of artistic license. (at least that’s my story and I’m sticking to it!) plus as I said, skulls are cool! I’d love to unpack why they’re cool, but for now, just trust me!