This expansion runs on the same client as Catacombs and as such you are required to have the Catacombs expansion to run Darkness Rising. So what does Darkness Rising offer you in terms of new features? The truth is, not a lot, you get a shiny new Champion weapon specific to your class, an horse to allow you to cross the realm at greater speeds than of those possible on foot, Champion Levels (These allow players to go beyond level 50, with five new champion levels) and subclassing (this allows champion to gain additional abilities from other classes).