#cbc

Sonic's hairstyle is based on this [fig 1]. Shadow's hairstyle is just Sonic's but like slicked down and longer

Shadow's eyebrows are based on kabuki theater makeup [fig 2], which was the inspiration for his markings

The earrings and the hair ring whatever are inhibitor rings. Except they don't suppress his chaos energy, they suppress his aura

I was GONNA make one of them lighter but since they're "copies" of each other, I thought "wouldn't it make more sense if they were the same shade"

Shadow's eyes are just Sonic's eyes but the top lid is lower. Like I just drew a line through the eye from one corner to the other and erased the top

The swirls and lines in/on their hair are meant to get across the fact they do NOT have straight hair. It's just coily and neatly packed together into "spines"

Refs