I know you, Eli Sanguine
Some mirrors act as a doorway to other worlds. But Eli can't sense any wavelength from this mirror.
"You know it," Se Ye answers. "Acrimony is full of bitter mirages. It's as vague as the reflection in the water that can be disturbed by simple waves alone."
The world can't be anything other than an illusion, just like the illusions that it shows to people. In the worlds of absolutes, illusions only exist when it's being observed. Nell can witness it because she is inside it. She is an observer and a participant.
Clearly, the mirror refuses to let go of Nell. The longer Nell stays there, the harder it will be for her to leave the mirror.
"Let's find a god," Eli says, "We will break this seal and get her out of this."
***
Eli stares at his reflection in the bathroom mirror.
The human is asleep on the bed, but he can't sleep. Although she didn't kick him out of the hotel room earlier, she refused to let him sleep on the bed.