The only remnant of the Shattering, Lydecker Cain found himself the solitary survivor of a universe that was no more than shards of glass.

"Have you ever felt like there’s a world just beyond ours? Some sort of strange dimension, a light dancing just beyond our fingertips? Well, I’ve touched that ‘sacred’ world, and I know its true face."

Codex

History is full of interesting and exotic people who can help to populate your world.  They can help illuminate the range of what people think is possible for your world (or you can consider them PCs run by players not in your game).