Villains suggestions for a campaign

Currently I am trying to write a part of a three part campaign that sends the party hopping through dread domains, always on the back foot trying to escape the dread domains and somehow they always seem to end up going further into them before they finally escape. I decided I want to home brew my own dread domains as a writing exercise. I may or may not use them but I want villains to model the Darklords of these home brew dread domains after. Currently I am planning on using Strahd because I feel like you can't go into the dread domains without stopping in Barovia. However I have outlines for domains with the dark lords being modeled after Konrad Kurze from Warhammer 40k and Judge Holden from Blood Meridian. I am looking for suggestions of other villains from literature and film that would make good dark lords. Any suggestions are appreciated!