An Entirety consists of all universes, all timelines, all dimensions, all Realities.
...So what happens when an author arbitrarily decides to say "okay but here's a second one?"
An Entirety's boundaries are defined exclusively by the fact that one cannot travel between them under any circumstances. Except for like extremely specific circumstances like being an agent of Chaos who is not bound to any Entirety. But OTHER THAN THAT, no crossing whatsoever!! If someone ever pulled that off you would now just have one Entirety, not two. Boy, I bet that would make for a pretty great plot twist, to spend literal years pretending crossing Entireties was real only to reveal that that would cause a merge instead and now Some Shit is about to happen!
Haha yeah that would be wild well I'm sure something like that would never happ
An Entirety with no one specific event separating it from Ent1rety (the baseline for my OCs). For many settings it serves as a "good end" AU, but this is hardly universal. Memen broke out and destroyed Hadris's entire empire long ago, for one thing, slaughtering a good chunk of my OCs and leaving many worlds disconnected. It was a good end for her, at least...?
In En2rety, Opine Frazil destroyed the Test Reality, leaving Dicro Corrune with no one to turn to other than an equally wronged and vengeful Ignis Phasmatis. This would prove to not only be Opine's undoing, but all of Entirety's, her underestimation of their power and drive leading directly into their conquering of all of Entirety.
En2rety is an Entirety as grim as it is purple. Dicro hit rock bottom and found a way to dig deeper, and with no one to serve as his morality chain no one could hold Ignis back from conquering everything in sight. Most protagonists in En2rety have been killed or enslaved while antagonists thrive under Ignis's rule, the only glimmer of hope lying with a resistance force that grows smaller by the day. The future seems grim, and that was before Ignis and Dicro found out out the latter happens to be the reincarnation of God themself...
A specific spin on En2rety in which Orchid found himself no longer able to tolerate Ignis or the Infernal Empire. Freeing his captive girlfriend from a horrific bout of torture, Orchid found himself fleeing to the resistance and becoming part of it. This led to Orchid learning of his divine nature and attaining said power... before donning the name Coris and vanishing entirely, merely promising that he would return someday.
Coris didn't leave Al2rety high and dry, however. His parting gift was a loud announcement to all of Entirety that he was betraying the empire, followed by publicly stripping Ignis and his most prominent sycophants of all of their powers, including the hold that Ignis had over the souls of many. He gave a few extra treats to the resistance as well, and ultimately intends to return once he's capable of saving Al2rety without relying on Frenzael's power.
With hope for a better future washing over Entirety, the resistance got a significant rush of members. With all of their new goodies and and a renewed sense of resolve, the resistance at last has a real chance of overthrowing the empire. They've already made significant amount of progress, and things are only looking up from here.
However, the resistance is the only one with a renewed sense of resolve. If there is one thing Ignis can't stand, it's betrayal, and a betrayal so vocal by the only person he could really trust?
Vengeance is where this Entirety began, and vengeance is how it will end.