When Dewnt became immortal at the end of the Third Age, she feared becoming like the vampires that had been a failed experiment in that direction and required human blood for their survival as nothing had been found to be a viable substitute. The chromasomal rewriting process that the treatment required had negative side-effects for Dewnt, further harming her perception of the process. And then she met Shönäl, who made her his Scion. Being a representative and agent for the god of Death added insult to injury. While her opinion has improved (she greatly respects Shönäl's goal of properly guiding people through the process of death), she still struggles with the perceived implications even after 2000 years.
Dewnt respects Shönäl more than she lets on. However, she struggles significantly with the implications of her position. Shönäl, on the other hand, highly respects Dewnt and her abilities, skills, and insights. He only wishes she would more tightly embrace her role as his representative. This is why he treats her more harshly than he would like.