Fai's skin is soft, and smooth, and very, very sensitive. Especially on his back – Kurogane likes to think it's his touch that makes Fai shudder and arch, but really he knows that it's because Fai's back is where the tattoo used to be.
And yet, Kurogane loves to caress his back, and watch his eyes flutter closed.
Fai is pale from head to toe, a testimony of a life spent in a cold climate, covered in warm clothing. His hair, too, is a pale blonde in colour.
All is pale but his eyes, which sparkle when he calls Kurogane nicknames.
Kurogane's skin is broken in some places, marred by mementos of various battles and skirmishes, from his world and from many others. The skin is lighter, smoother, and infinitely more sensitive around the many scars.
Fai cherishes each and every one, memorizing them with long, slender fingers in the darkness.
Kurogane is tan compared to Fai, his skin browned by the sun of his world and many days spent training outdoors. Kurogane is rough and dark and mysterious, and Fai enjoys figuring him out.
But most of all, Fai enjoys the fire in Kurogane's eyes when he calls him nicknames.