Ulurslef

Ulurslef is one of many names for the entity which has appeared in many places, many times, with many faces. It has been a demon at a crossroads ready to make a deal, it has been the fearsome Rynald MycDynalds who started a conjuration restaurant, it has been the mysterious traveling Salesman, it has been so many things. Few of them are specifically evil or good, but it always seems to benefit. 
Ulurslef is a powerful eldritch entity from somewhere beyond the normal planes. They love to make deals and manipulate others into their service, such as when they wiped the minds of some warlocks to retake a book of control tied to Ulurslef from the Zendarru Nightfall Hold. When those warlocks realized the manipulation, they used the book, banishing the entity to wherever it came from. However, with Maria's help recovering the book and Chi Pin's help reading it, Ulurslef returned to the material plane.