Darth Dougan

Darth Dougan was a Sith Lord in the time of Jeoth Huudson and her brother, Keesth Huudson. They both battled Dougan at some point, and although Keesth allied him for a short time, they are all supposed to have no relationship between each other.

Jeoth fought Dougan a little earlier than Keesth, although Keesth was defeated.

Dougan was strange, not really caring about the Only Two rule, he actually had 11 apprentices in total. All of them have been supposed killed.

It is unknown if it was Dougan that lured Keesth to the dark side, but if it is, no one would have any knowledge of it.