From what I got from the Digimon series (and its different seasons) is the fact that, like Dc and Marvel comics, is subjected to the theory of multiple universes.
Several variations of Earth and its neighboring Digiworld are on the menu, at least 12 registered realities (but according to Shukumeimon there are WAY more!) and they’ll be sooner or later dragged (without any sort of escape) into a wacky race for survival.
Digidestineds, digimons from 12 realities will either join forces or fight against each other in order to win. Who’s right and who’s wrong? Who’s the one who deserves to win the most?
Below, the “Guide to the Digi-Multiverse”:
Reality 01 Reality 02 Reality 03
Adventures 01-02 V-Tamer (Manga) Tamers
Reality 04 Reality 05 Reality 06
Frontiers Data Squad X-ROS/ Fusion
Reality 07 Reality 08 Reality 09
World Dawn &Dusk X Next (Manga)
Reality 010 Reality 011 Reality 012
D-Cyber (Manga) Cyber Sleuth- Re:Digitize Cavaliers
Note: Reality 011 is actually partitioned into3 realities: α,β and γ.
α corresponds to Takumi Aiba’s reality, β has Ami Aiba as the protagnist while γ corresponds to Re: Digitilize
Because of a shared irresponsibility by Tempus Angemon and Nova and their subsequent actions brought an alteration in the fabric of time, in a rush to save Magnus Takariyam’s life in reality 09 the original timeline from reality 01 was wiped out and replaced by a distopian one. It became the “Omega effect” because its consequences were so chaotic that ended causing disruptions in other realities’ timelines as well (especially in reality 03 and reality 09)
Tempus Angemon and Nova were forced to recurreto extraordinary (and quite painful) measures to correct their mistake. But Saturn Angemon wants to bring it back…