"Soul eater" - an ahumanblight that infected biont victims in the Inner Sphere during the Federation Era, assuming control over their higher functions using a technocyte infestation. The most famous example of psychophager infection is the MyuvYin Gestalt, a group mind that formed after the Gl 205 system was afflicted in 1201 AT.
A typical psychophager affliction would retain as many of the victim's memories, skills, and capabilities as possible, while replacing the victim's personality with a new, artificial version connected to the ahuman group mind. However the subsumption process was often problematic, since the original personality sometimes attempted to reassert itself. Bionts captured by psychophagers rarely lasted more than a few years in their original form, but are then replaced by identical cloned copies, or cyborgised to ensure greater sustainability.
Sometimes the original biont is replaced by an exact clone with no visible modifications, and these unmodified entities were used as representatives which could engage with outsiders while appearing entirely uninfected, gaining their trust and maximising the number of potential victims. The technocyte infections were usually accompanied by various kinds of advanced malware that further reduced the resistance of the targets.
Not surprisingly, psychophagers were among the most despised of all ahuman factions (at least among bionts). After the emergence of the Sephirotic Gods the psychophager blight was largely eliminated in the Inner Sphere, although outbreaks of similar pathologies occasionally emerge in the Periphery.