Complex sentence: After gaining popularity with the viewing public, Malarkey's role was upgraded to a series regular in season 6 and 7, he was added to the main cast for the eighth and final season of the show.
Split into simpler sentences: After gaining popularity with the viewing public, Malarkey's role was upgraded to a series regular in season 6 and 7. He was added to the main cast for the eighth and final season of the show.