"Uncle Humblestaff?" the young hero responded. "Of course I know the man. Wouldn't have had a chance at the academy without a word from him. He's the big guy over there, surrounded by all those adventurers."
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."
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).
Pick up a pathology/microbiology book, and add the diseases/syndroms to your game. Your players will freak out.
Coughed at? Diphteria. or tuberculosis?
Drunk from a muddy stream? Or just walked through? Well, let us introduce you to schistosomiasis...
Hit by a stream of energy? Too moch mana is ust like too much radioactivity - perhaps all mages could develop cancer early if too powerful...