недовыяснены отношения с Небывальщиной

рыцарь Зимнего двора

Фомором, потому что Фоморы — извечные враги Туата де Данаан, см. ирландскую мифологию

демонический пес

Тот Кто Идет Следом.

   Леанансидхе чуть откинула назад голову и тихо рассмеялась.
   — Вы здесь далеки от источников своей силы, мой дорогой демон.
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   Леанансидхе медленно покачала головой.
   — Как Дрезден вообще одолел Вас?

Uriel stood over us, smiling down, but said nothing.
“Missed you, too, boy,” I said. “Just . . . kind of stopping by to say good-bye.”
Mouse’s tail stopped wagging. His big, doggy eyes regarded me very seriously, and then glanced at Uriel.
“What has begun must finish, little brother,” Uriel said. “Your task here is not yet over.”
Mouse regarded the archangel for a moment and then huffed out a breath in a huge sigh and leaned against me.

А He Who Walks Behind все-таки Outsider (Иной) и вряд ли архангел стал бы называть его маленьким братом.

Кроме того, Уриил явно указал, что Мыш это храмовая собака:

“Temple dogs have been known to live for centuries,” he replied. “Your friend is more than capable of protecting her for a lifetime—even a wizard’s lifetime, if need be.”

The Walker had never been trying to kill me. If it had wanted to do that, it didn’t need to play with me. It could simply have appeared and executed me, the way it had poor Stan at the gas station. It had been trying to push me, to shape me into something dangerous—like maybe a weapon.

I had always assumed that Justin had controlled He Who Walks Behind, that my old master had sent him after me when I fled. But what if I’d been a flipping idiot? What if their relationship had worked the other way around? What if Justin, who had betrayed me, had similarly been backstabbed by his own inhuman mentor, when the creature had, in essence, prepared me to destroy Justin?

(курсив Джима Батчера)

Since I'd stolen him from Justin DuMorne, my own personal childhood Darth Vader, Bob's knowledge and skills had let me save lives. Mostly my own, maybe, but a lot of other lives, too.