Wights

A Wight is created when an Unclaimed Spirit gives its Soul to Hess after they have died, when they do this their sentience is restored to their body and their body becomes animated, regardless of whatever state it was in when they died.
The outward appearance of a Wight is similar to an animated dead, their looks vary depending on their level of decay and preservation, their bodies continue to decay, however, so older wights tend to be skeletal or mummified.
Like other soulless undead, wights yearn for a soul, many fulfil this need by bargaining with mortals for their souls via demonology. Especially powerful Wights who are usually trained in a variety of the Arcane Arts are often called a Lich.