Morthander is the kind of character you love to hate. He is no hero.
He is an antihero. He kills for fun. He kills hazia addicts and
women who have been enslaved into lives of prostitution. He would
definitely say something along the lines of "Kill them all and let
the Red Goddess sort them out" while conquering a suspected center of
rebellion against the empire. People like Morthander tend to get
really powerful, but not by themselves. They tend to accumulate large
armies and political parties around them, and then either they
succeed wildly or they get poisoned in their sleep.
I like Morthander. I just don't like his name. No gentle-caste
Carmanian would carry a bizarre name such as Deville. More likely
his real name is Morekadar Drachilla, and he has disguised his name
to avoid repercussions to his birth house.