The Devil Knights

Enma and Yokai were two powerful infernal entities associated with death, said to collect the flesh and souls of the unworthy in death. Portrayed as brothers, they were malicious and unforgiving, with one, Enma, favoring wild and uncontrolled bloodshed, and the other, Yokai, preferring complete obedience and tyranny. 

Despite their previous influence and importance in the cosmology, they were said to be servants of a much darker force associated with the unholy dead. 

Influence after the Calamity

Following the events of the Calamity the Devil Knights were unable to maintain influence via their many cults throughout the region, and they eventually faded into obscurity. They are said to occasionally appear near openings to the Ethereal Plane to barter with unwitting mortals that get to close to their former domain. 

The few records of them today list them along many other deities that are now considered vestiges - inactive divine powers. 

Enma

Enma were portrayed as a red-skinned vicious devil with a grinning mask covering his face. He was associated with cannibalism, the spilling of blood, and the desecration of flesh and bone. He was reckless and vicious, and obsessed with the purity of demonic bloodlines. He was also known to be skilled with the flute and an excellent dancer. 

A Looming Presence

Valkyrie had a connection to Enma, and learned that she was a product of fleshcrafting. For many weeks, Valkyrie was in possession of the Tooth of the Dancing Devil, which she was unable to let go off, until its true purpose was revealed much later - a keystone to opening a rift between worlds and planes, allowing Enma to enter the material plane in some form and shape. 

When the party entered Farhold, and Valkyrie was pulled into the demiplane of Enma and Yokai by an arcanaloth, she escaped into a ritual scene unfolding with Folduin Caerlinn and Celydia Caerlinn. The tooth began to animate and seek out the fleshcrafted portal she had walked through, permanently creating a doorway for Enma to enter the world, albeit in Farhold rather than in Wyldenhaal. 

Yokai

Yokai were portrayed as an ominous samurai-like figure completely covered in armor and blue robes that were constantly swaying around him. Like his brother, he wore a grinning mask to cover his true face, which were said to be completely hollow. He was a disciplined and merciless fighter that absorbed the souls of his defeated foes while his brother consumed their flesh. A skilled musician with the shamisen (a sort of string instrument), his melodies were said to tear the souls of unworthy mortals and instantly kill them. he was also known to be a painter.