The Door Within is a Christian YA fantasy trilogy written by Wayne Thomas Batson. The central premise of this trilogy is that another world, the Realm, exists parallel to Earth. The Realm could be seen as "the spiritual made physical," and travel between the worlds is possible. As it is a YA series, the humans who go to the Realm are teenagers. The inhabitants of the Realm are called Glimpses; they are completely identical to humans, except for their ghost-white (to the point of seeming to glow in dim light) skin, and their eyes. A Glimpse's eyes will "glint" one of three colors, signalling their loyalty: blue for King Eliam, green for the undecided, and red for those who follow Paragor the Deceiver. You have three guesses as to who Paragor and Eliam are meant to represent. The first two don't count.
It should be noted that the Realm and Earth (or the "Mirror Realm" as the Glimpses call it) are not only parallel; they are linked inextricably. Every human has a Glimpse twin. These twins are identical to them physically, although they may be a different age. What each person does influences their twin, and the two—despite differences in age and circumstance—will die at the same time. What a human believes in regards to the Story (this universe's Bible, essentially) will show in his Glimpse's eyes, and what a Glimpse believes about King Eliam will influence his human twin.
In the PPC
There are a whopping six stories for The Door Within in the Pit, and despite the alluring world of prophecies, unicorns, dragons, knights, really awesome food, and evil dark lords, none of them have Suvian OCs. Thus, there are no missions in this continuum yet. The PPC does have a Glimpse agent, however.
Because King Eliam is basically the God of the Bible, He knows about the PPC. He has yet to say anything, though.