retcon → αλλάζω αναδρομικά ιστορικό χαρακτήρα, αναδρομική αλλαγή ιστορικού χαρακτήρα
(in a film, television series, or other fictional work) a piece of new information that imposes a different interpretation on previously described events, typically used to facilitate a dramatic plot shift or account for an inconsistency.
Revise (an aspect of a fictional work) retrospectively, typically by introducing a piece of new information that imposes a different interpretation on previously described events.
https://en.oxforddictionaries.com/definition/us/retconhttps://www.onelook.com/?loc=bm6&w=retcon(shortened form of RETroactive CONtinuity; first made popular in the comic book world)
1. (original meaning) Adding information to the back story of a fictional character or world, without invalidating that which had gone before.
https://www.urbandictionary.com/define.php?term=retconRetroactive continuity, or retcon for short, is a literary device in which established facts in a fictional work are adjusted, ignored, or contradicted by a subsequently published work which breaks continuity with the former.
https://en.wikipedia.org/wiki/Retroactive_continuity