I was also thinking that JB may be the Unseelie King because of the torque and that the shades don't seem to bother him and seem to move away from him when he passed by them. Adam Black's torque and armcuffs were gold and the one's JB has are silver and black, but it is still a possibility. I also believe that if he was the Unseelie king he could cast enough glamour that Mac may not be able to penetrate it, because according to the definition the more powerful the fae the harder it is to penetrate their disguise. Mac has also just bagan to understand her powers and may not be at her full abilities.
I just reread Immortal and it said that Darroc's torque and armbands are black, JB's torque if I remember is black and silver and Adams are gold. I am wondering if maybe the Seelie the light fae wear gold thus light and the Unseelie wear black or black and silver thus dark. I don't know just a dumb thought there. And as was brought up before in Into the dreaming the Unseelie King has been missing for about 30 years which to me seems fishy.