Dark Fury

Acquisition
Skill Trainers:
 * Harnil (Marhan's Grotto)
 * Dakk (Ember Light Camp)

Related skills

 * Order of Pain
 * Order of the Vampire (Elite)
 * Order of Apostasy (Elite)
 * Order of Undeath (Elite)

Note
While the text says "nearby", it actually means everyone in radar range.