There is more to Zak than meets the eye: For someone from the void, he looks human, acts human and speaks human languages pretty fluently. Truth is: Zakai is a demon and acts as death in this world. Contray to soul hunters and tales about Death itself, he is not allowed to take lives but only to guide the souls of the dead to the afterlife.
Zak often sees his task as a punishment and doesn’t get along with fellow demons, so he tries to stay out of the void. To keep distance to the demon world, he built himself an identity in our world as the barkeeper of the “Wolf’s Den”, a bar he and his ‘sister’ opened a few years ago. His powers are limited, but enough to keep a low profile while living in our world.