I created Slieve for a player who wanted a demon character. He was inspired by Yu Yu Hakusho, which made this one a challenge. I find the treatment of "demons", and other supernatural creatures, to often be in poor taste. By which I mean the mythos is lazy. Too often, supernatural creatures are just humans with wings or lasers or immortality. That works if you literally wanted supernatural creatures to just be a variant of humanity, but oftentimes the line is blurry between "they're like us, but..." and "they're alien". These are things that can be done well; they just usually are not.

So, I took that concept here and spun it as well as I could into something that still worked: yes, he looks fairly human, and yes, he's violent; but it's more than that - he's hardwired for violence and attention. It's a subtle difference that helps define the character as something other than "us".