Long ago, a woman named Opine Frazil died and found herself in Limbo. She was offered a Promotion to become one of Them: an almighty group of entities who resided on the very fringes of Entirety and were able to travel between Realities freely. She accepted, and upon becoming one of Them was granted a Request: a limitless wish able to bend reality. Her Request was to create "the perfect game," granting her unlimited power for the purposes of allowing her to accomplish her goals.
Opine created a pocket dimension called the Test Reality, isolated from all other realms. She populated with soul-based humanoids she called the Tested, then ordered them to compete in the Competition: a battle royale where the last Tested standing would be granted a Promotion like she was. This first Competition ended in disaster: the Tested that Opine had created to serve as a villain succeeded far beyond Opine's expectations, slaughtering her fellow Tested quickly and effortlessly. Nonetheless this villain had to be given a Promotion, and she used her Request to cruelly sabotage the runner-up's life. Distraught that her years of planning had gone to waste, Opine threw the remaining Tested's souls into the reincarnation cycle and abandoned the Test Reality.
Thousands of years later Opine created a new Test Reality and a new batch of Tested to go with it. In order to keep things more balanced she introduced the Oresses: magical orbs that granted powerful abilities to those whose souls were bound to them. She also introduced "Unreal" people - soulless background characters - to allow the Tested to have backstories without needing to create superfluous characters and muddle her work. Once everyone had reached their proper age, Opine announced that the beginning of a new Competition was imminent. The Tested scrambled to form alliances and train, struggling to come to terms with the reality of their existence as playthings to an unpleasable god.
In the canon version of the story, who knows what happens? But in the RPverse version of the story, this second Competition ended with an insignificant Oress Holder winning due to some clever cheating. Enraged, Opine managed to deny his Promotion and opened up the Test Reality to other Realities, dragging in other beings and forcing them into participating in Competitions over and over again. The Tested have gone through numerous
plot reboots memory wipes and universe resets, never sure how long periods of peace will last. Their situation is more precarious than ever, and even They don't know how to take away Opine's power...
By default, many of the Oress Holders chose to stay at Castle Oress with the others, forming the Castle Oress Alliance. Technically led by Cel due to her vague memories of her prior life making her seem important, the Castle Oress Alliance is considered the "good guy" alliance. Especially in the RPverse, the Castle Oress alliance is associated with both the heroic and defenseless, its members seeking to find a way to end the Competition with as little bloodshed as possible.
Led by Umbra Tear, the creator of the Oresses, Umbra's Alliance is considered - especially in the RPverse - to be the "villains" of the Test Reality. They take most of the initiative in Competitions, wasting little time in getting to the killing. The truth is more complex than bloodlust, though, at least for the core members. Umbra simply seeks to end the Competitions as quickly as possible to minimize suffering. Playing the part of the villain and not being morally picky with her recruits just makes it easier for the other Tested to stomach fighting against her.
Led by the Manipulator, Halyn - an offworld overseer of the Test Reality, not a participant in the Competition - Halyn's Alliance is an odd case. It consists of the Tested who didn't become Oress Holders, each having already had their own powers to defend themselves with. Halyn picked them up prior to the Oresses being assigned and suggested an alliance to keep them from getting picked off by the others, to which they agreed. Though they seem like neutral territory - especially with their lighthearted personalities and casual responses to danger and the unknown - in truth they have an agreement with Umbra's Alliance. They won't harm each other's group until everyone else is dead, then it's alliance vs alliance.
Not all of the Tested chose to join one of the major three alliances. A number of Oress Holders instead struck out on their own or formed partnerships, to wildly mixed results.
No matter where they're from, all souls in Entirety come to Limbo upon death, even if only for a fraction of a second to be diverted to their proper afterlife. A number of beings from across Entirety work here, mostly spending their days doing paperwork to make sure everywhere's going where it needs to.
Limbo has a close relationship with the Test Reality, as it houses those who die there until the end of the Competition. Many of Limbo's workers are Them on top of it all, with Them having an even stronger connection to the Test Reality. The Tested are quite familiar with Limbo and its residents, taking a seat and grabbing some froyo while they try to cope with their demise - and the inevitability of going through another.
Existing on the outer fringe of Entirety in a place called There - the border between Entirety and the nothingness beyond - They are the ultimate beings of Entirety. Sort of. They might be the highest on the Chain - excepting the Superior Beings - but They don't have the godlike power one would assume. All of Them have the ability to freely travel between Realities, instantly warp back to There, and elevate their Vibe to scramble the brains of lower beings, but that's about it. Plenty of beings below Them are capable of warping reality itself, but They have no such innate abilities.
This is because becoming one of Them is an afterlife. When a soul reaches Limbo, it is automatically marked if it is eligible for Promotion. Promotion can be denied - if so, that soul will move on to its normal afterlife - but if accepted the soul is taken to a room where no one quite remembers what happens. The soul will become one of Them, maintaining any of their old abilities and only gaining the few that being one of Them grants them and subsequently being moved over There. They are given a Request, which they can use at any time: a Request is essentially one free wish that can completely warp reality, granting the requester whatever they ask for.
Despite the efforts of Their research, no one is entirely sure what makes one eligible for Promotion. None of the lists out there seem to fully apply. Gods and great heroes exist among Them, but so do completely mundane (former) mortals and joke characters. In fact, most of the populace consists of the chaotic and lackadaisical, making it seem as though eligibility is completely random.
There is one exception, though: a proper Request can allow one to Promote whoever they choose. Opine Frazil has abused this by keeping her Request vague, allowing her to Promote anyone who wins a Competition. While Their existence is a secret to the rest of Entirety, the Test Reality are well aware of Them thanks to Opine. They've developed a strong relationship with the Tested, with the Competition being viewable on any TV over There and many of Them dropping in like it's some sort of tourist joint.