Filin

 was a Gendar, and a past host of the Gestalt long before Kady Williams. She was smaller and slimmer than Kady.

Filin was approached by "Them", the beings Chris Cwej knew as his "Superiors", with a deal: they needed the Gestalt's expertise to operate on an aberrant Cwej who had fallen through time, to turn it into a unique memetic weapon. In exchange, they would "nudge" the timeline of the planet Gendar to avert a then-imminent catastrophe. The minds within the Gestalt were split on what to do, and Filin ultimately agreed to the deal, although she regretted it almost immediately after she started performing the operation, realising that the transformation was painful and non-consensual for the entity. The entity, now calling itself the Gentleman, soon proved impossible to control and the Superiors had Filin track it down and imprison it in their prison. However, the Gentleman remained linked to Filin and gave her nightmarish visions where it destroyed Gendar, making sure she would "never forget what [she] had done".

After Kady Williams, a much later host of the repentant Gestalt, crossed paths with the Gentleman again, the Gentleman informed Kady of his past history with the Gestalt. The Gestalt reluctantly allowed Kady to access Filin's memories so that she could get the whole story. (PROSE: Ring Theory)