Receptacle SE-280
Receptacle SE-280 was the Hesguard Institute designation for the sin-eater assigned to receive the negative emotions of the Ninth Doctor.
As with all sin-eaters, it was originally an artificial being intended to be a receptacle for a criminal's negative emotions that were artificially removed from the individual as part of the Institute's experimental Bad Wolf Process. The theory behind the process was that without the negative emotions and impulses that drove their crimes, patients would be unable to commit any more crimes. This would allow them to move on and subsequently be rehabilitated and released into society.
As part of a plan to infiltrate the Institute, the Ninth Doctor fabricated evidence that he had murdered his companion Tara Mishra. He was subsequently arrested and sent to the Institute for this and other perceived crimes. He was subjected to the procedure, despite the objections of Rose Tyler, who had come to the facility posing as a Earth Examiner.
The process backfired due the the Doctor's unique Time Lord physiology. Though sin eaters were originally non-sentient, the introduction of the Doctor's mind granted SE-280 a form a sentience and it, in turn, granted sentience to the entire population of sin-eaters. This turned them into monstrous creatures driven purely by the dark emotions that had formed them. They went on a rampage, killing many of the facility's personnel, including Director Hesguard.
SE-280 was ultimately defeated by the Ninth Doctor, who used the Director's emergency transmat device to teleport his doppelganger into the station's Matryoshka Drive and ejected the drive into the Void. Without the drive to power it, the station also dissolved into the Time storm, taking the remaining sin-eaters and any surviving personnel with it. (COMIC: Sin-Eaters)
In appearance Sin-Eaters appeared as featureless humanoids, until the process was completed, then they took on the featured of the patient whose emotions they absorbed. Though originally designed as non-sentient receptacles for emotions, the introduction of the Doctor's unique mind gave them all a form of sentience, turning them into monstrous being
