The Dresden Files: Portland
Transparent, faintly glowing, semi-corporeal figures.
What We Know
Spectres may not be naturally occurring ghosts. They may actually be ghosts “modified” via necromancy into a manifested construct form. Necromancers often use spectres as troops in mass conflicts.
Spectres seem to trade the bulk of their ghostly powers in favor of manifesting a translucent, semi-corporeal, ectoplasmic construct that’s stronger than a man and quick to heal (thanks to easily reconstituted ecto-flesh).
Standard ghost weaknesses plus—due to being forced into a semi-material form—spectres don’t seem to have the luxury of being able to ignore mortal reality and can be affected by anyone (not just those twho have magic, know their identity, and speak the ghost’s name aloud).