Mortals are what most folk are- humans and orcs and such. Born up, lives and dies, not a lot of magic just kicking around in ’em. The savant elaborated that any non-magical creature was natural enough to call a mortal. So, academically speaking you and I are in the same league as bears and lizards.
Wilders are made up of Fey magic. Elves and Eladrin are the most common example, but every fairy and fomorian qualifies as well. They’re pretty well known for their condescending stance on Mortal folks, and also for their tendency to keep us wee mortals as slaves. That’s not to say there aren’t some nice ones of course- I mean, one of my best friends is an elf.
Deaders are pretty much what they sound like- folks what used to be dead. Certain sorts of unwholesome shadow magic are flitting all around The Shatter, and when they make someone pop back up after they’ve stopped kicking that person is a deader. Now, there’s a handful of Deaders that are right sociable. Mostly, though, they’ll try and tear off your skin and eat it.
Demons are what you get when a big pile of raw elemental energy starts walking around. My savant buddy was quick to point out that Demons and Elementals are technically the same thing- it’s just that Demon has the connotation that they’re out to kill you. Well, from my experience pretty much every “Elemental” is out to kill you, so the term Demon works just fine for the lot. They’ve got some sort of feud with Devils, though they’ll never tell you why.
Devils are the immortal kin of the Gods. Now, again, technically Devils aren’t intrinsically evil. There’s some swell angels and suchlike. But fact is, they don’t have a great grasp on how to treat us mortal folks, so they tend to cause a ton of trouble. They hate Demons with a passion, so it’s usually in everyone’s best interest to keep them apart.
Blighters are always bad news. Far as the savant could explain it, a things a blighter when it’s made up entirely of corruption, madness, horror, and probably tentacles. If you’re lucky, they just kill you. They’ve got a penchant for crashing down on settlements and devouring the souls of anyone they find. Sometimes a Blighter comes ‘round a place acting reasonable and civilized, but it usually doesn’t take long ‘til they’re sucking out brains.