The priestess Serena sometimes aids the heroes, but she has also been known to work against them. The Descent: Journeys in the Dark (Second Edition) - Serena Lieutenant Pack includes two plastic figures for the hero and lieutenant versions of Serena. By using Serena's Hero sheet, you can wield her formidable magic for good, possibly healing the wounds of nearby heroes while rejuvenating their fatigue. Although Serena can be fragile in direct combat, her hero ability allows adjacent heroes to protect her against attacks, meaning that she can continue working for the greater good.
Serena may be a potent hero, but she can also take the field as an agent of the overlord, helping to defeat the heroes with her "Silent Protector" Plot deck. Each of your Civilized monsters will receive enhanced powers from Serena's Plot cards as she works to keep them fully healed. Simultaneously, Serena can incapacitate the heroes and slow them down with cards like Traveler's Rest.