Lord Festerus commanded the Death Guard host that emerged from great warp rifts near the Stygian Empire. He began attacking Imperial space in concert with the Alpha Legion and Stygian forces. Little was known to Imperial commanders about Festerus initially, Although that would change as he became a greater factor in the Stygian Wars. Like all Death Guard he favored the use of both chemical and biological warfare. Where he stood apart was in the tactical employment of pox walkers in brutal limited campaigns refered to as "Festering Wound" campaigns. In Such campaigns the Death Guard would raid a planet inflicting as many casualties and damage as possible in a short period of time, typically three days or less then withdraw to raid another planet. They would return a month later in force as pox walkers created from the first raid would be emerging as a planetary threat. The death guard assault from without and the pox walker festering wound from within would often see planets fall.