A flux was an individual whose history was continuously changing. One was created when an individual used a very high chaotic limiter setting to go backwards in time but not far in space, effectively turned loose in his or her own history. Because of the limiter setting, tiny actions taken by the future version would have very large effects on the past version, which would transform the future version's biodata and in turn alters the changes made to the past version.
Most fluxes lasted for only two or three cycles of change before either the death of either the person's future version (causing the process to limit itself) or the past version (causing the process to infinitely accelerate). However, if a stable balance was maintained, a Shift would be created.
The creation of stable fluxes was pioneered by the Celestis, whose realm of Mictlan was one giant flux. Other Celestis-invented applications of flux theory were anarchitects and gargoyles. However, in the first fifty years of the War, the Great Houses failed to produce any such balanced fluxes.
Faction Paradox used unstable, infinitely-accelerating fluxes to create its sombras que corta; because of the Faction's alter-time systems, the fluxed objects remained visible in shadow form instead of becoming purely theoretical as a result of the imbalance. Suicidal members of the Faction sometimes ritually killed themselves by murdering themselves as children. This would force their bodies into a flux state seen as divinely paradoxical, transforming the individual into a fugue-like structure of equations and making them feel closer to the loa. They survived only as shadows on the walls of the Eleven-Day Empire. (PROSE: The Book of the War) Grandfather Paradox was thought to have retired from history in this way. (PROSE: The Book of the War, The Gallifrey Chronicles)