Review Detail of KingHeart in Fury Towards The Burning Heaven

"The Netherworld King's long grey hair fluttered despite the lack of wind" I really don't understand why the author must write this line in prologue chapter. from my understanding, this netherworld king is a skeleton figure. so, where are those hairs attached in his head? did they grow in the bone skull? Did hair suppose to grow and attached in the scalp?