Paul Thorburn is the son of Rose Thorburn Sr., brother of Charles Thorburn, Irene Walker and Bradley Thorburn, as well as the father of the most children including Kathryn Thorburn, Paige Thorburn, Peter Thorburn, and Ellie Thorburn by his ex-wife Stephanie Thorburn, and Roxanne Thorburn as well as James Thorburn by his second wife, Jessica Thorburn.
He and his ex-wife split apart and he took only Paige, leaving the other two with her and causing animosity between them.
In the story proper he first appears in the opening chapter at the death bed of his mother, where all of his family had gathered. He later appears during the "Malfeasance" arc in order to try and oust Rose from the Hillglades House.
More or less presentable.
At the time of the story the rift between him and his ex-wife, along with his son, Peter, and daughter, Ellie, makes it clear that he saw Paige as the only one who he cared about at the time, adding to the family division. He's adamant in getting the household and ousting Rose, being the one who seems to lead the effort on their family's side of things. He also seems to dote on his daughter to the point where she's become spoiled rotten.
Peter notes he's pretty much ruined all of his children. He told Kathryn to make herself successful and never forgave her for aiming low. He told Paige how to be successful and it nearly tore her apart. James is being coddled so they can use him as a puppet, but Peter suspects they'll break him like everything else and they haven't even started on Roxanne yet.