The Doben Followers is a term used on people who follow the god of evil named Doben. They do not necessarily have to be corrupted, they can also be following him out of sheer loyalty.
Appearance in the show
When Season 2 rolled around, Doben corrupted the air in Skyrim, turning people to his side, killing anyone who didn't like his new regime. Doben followers can appear anywhere, and their armor and weapons vary greatly, from peasant gear to full-blown daedric goodness.
Since Doben has control over the cities in Season 2, the Jarls have turned into Death Jarls, which is a more powerful version of themself. This is another example of a Doben Follower. They often have dark or red eyes.