There are currently three areas in the story; "The Forest", "The Marshlands" and "The Deserted Peaks" (the last name is a subject to change)
Intelligence (as the nightmare) is canonically dead, killed by the main protagonist. However, before his death he could appear both in the Forest and Marshlands. He'd behave differently in both areas. In the forest, he'd stay closer to the river banks near the border to the "Marshlands" which he'd guard. Intelligence would look into small hiding spots, climb on trees, etc. to find any travellers. You'd have to sneak around that area in order to move forward to the "Marshlands" which is a potential step closer to the exit. If Intelligence spotted you, he is slightly faster than avarage, and outrunning him is hard.

Minkstep is Mire, Flamepatch is Shriek and Rookshade is still a traveller who is currently alive, wandering through the "Deserted peaks" She stays there since exept for Leap, the Harsh weather and Shiver, its practically safe and not littered with Nightmares (yet)

There are waaaaay more nightmares than in this book, but they simply don't have a design or an idea.

Not all dead characters become nightmares but most do.

Some unmentioned characters ars; Track, Fir, Fear and Leap. Some wip characters include Avoid and Difference, but those might be scrapped in the near future.