Phantoms

A curious form of undead, phantoms are completely invisible to the naked eye, save for their swords and shields. Other than their supernatural existence, phantoms appear to have no particular special abilities, but are fairly difficult to defeat without dispelling magic.

Phantoms are commonly found in dungeons, and other sites where they met their demise in battle. Interestingly, they could occasionally be found in the company of wisps at the start of the Age of Enlightenment.