Mistwraiths were a species of creatures on Scadrial.
Like kandra, they appear to be amorphous blobs capable of absorbing bones and tissue of other creatures to gain shape. However, unlike kandra, since they do not possess sentience, their shapes are random and mix many different species into one. They are usually humongous and are fearful existences in skaa folklore, associated with skaa's fear toward mists. But contradictory to their unnerving appearance, they are actually quite harmless and only eat dead bodies. 
Mistwraiths are people who have a blockage between the Physical Realm and the Cognitive Realm, which impairs their ability to think. Mistwraiths have a lifespan of roughly fifty years, and are able to breed.
Relation with Kandra
Through the use of Hemalurgy they could regain the sentience they once possessed, becoming kandra after being implanted with two Hemalurgic spikes. MeLaan mentions that removing both spikes brings the kandra back to their "primal state," once again becoming a mistwraith.. The transformation from mistwraith back to kandra is quick, as evidenced when Wayne replaces MeLaan's spikes after she experiences this firsthand, although this could depend on how much time passes between each state.
The transition from mistwraith to kandra requires specific types of Hemalurgic spikes, known as blessings. Other types of Hemalurgic spikes, such as those that create koloss, would not necessarily be enough to transform the mistwraith into a kandra, however they would cause weird side effects.
- It is possible to staple a cognitive shadow to a mistwraith with one Hemalugic spike.
- The Hero of Ages chapter 68 epigraph#
- The Bands of Mourning chapter 12#
- The Final Empire chapter 8#
- The Final Empire prologue#
- 17th Shard Forum Q&A
— Arcanum - 2012-09-27#
- The Hero of Ages Annotations
— Arcanum - 2010-05-27#
- Berlin signing
— Arcanum - 2019-05-14#
- The Hero of Ages chapter 62#
- Shadows of Self chapter 13#
- The Bands of Mourning chapter 29#
- Barnes & Noble B-Fest 2016
— Arcanum - 2016-06-11#
|Era 1 books||Mistborn: The Final Empire · The Well of Ascension · The Hero of Ages · (Mistborn: Secret History · The Eleventh Metal)|
|Era 2 books||The Alloy of Law · Shadows of Self · The Bands of Mourning · The Lost Metal · (Allomancer Jak and the Pits of Eltania)|
|Shards||Preservation · Ruin · Harmony|
|History||Classical Scadrial · Final Empire · Catacendre · Elendel · Southern Scadrian|
|Magic||Metallic Arts (Allomancy, Feruchemy, Hemalurgy) · Metalborn · Mistborn · Misting · Savant · Ferring · Twinborn · Compounding · Atium · Lerasium · Ettmetal|
|Other Media||Mistborn Adventure Game · Mistborn: Birthright · Mistborn film · Mistborn: House War|