This school of magic allows past events to be changed to mesh with current needs. It is theorized that only the Titans have access to the powers of Retconjuration as it is too powerful for a mere mortal to comprehend even its smallest of ramifications. Being a very volatile subject, it is usually avoided in most public forums and viewpoints on the subject differ greatly.
The school of Retconjuration is notable for being an example of itself; the Numbers axis of Naughtymancy was an entirely different school called "Deletionism" until the Titans realized that Retconjuration would be necessary for them to properly maintain Erfworld.
Mortal users of Retconjuration would be in position to engage each other in a war of existential reconstruction, up to the point that only a timeline where they were all erased would be stable. Of course, as there have been no mortal Retconjurers, this is not possible.
The name refers to "retcon", short for "retroactive continuity", in which the history of a fictional setting is be changed after publishing to mesh better with the current desires of the author. This is ironic because this form of mancy is itself a retcon.