Valencina, Salvador fought the Lord of the Flies. Gregor is a literally walking nuke. Outis is once a high-ranking officer. And Roland? The only thing we know is he fighting in it and seeing Old L Corp's Singularity
(In my timezone, it's Saturday)
(Why I have a feeling that I see it somewhere befofe ... red & black clothings; pale skin & dark hair; heterochromiac eyes, one red & one yellow; and the left eye has clock symbol)
He has tricks that make number and raw power meaningless.
Stygian shades - the stronger the enemy is, the stronger the shade is, same with number
Teleporting himself and other object around more efficently than W corp tech.
Sealing power
And so on
Argalia is immune to gun, has space rending, and is probably more skilled in swinging scythe than Rien.
(I did post it in Saturday, in my timezone it's already morning when I post it, apologize if some area is not even Saturday yet)
The theory is that he once lived in an area controlled by The Ring's Corporists where corpse-crafting has became common due to The Ring's influence.
First, there're two clear connections. Albina and his puppets share the technique "Repressed Flesh", and his dedication to satisfly his turmoil through crafting puppets by corpse aligning with the School of Corporism.
Therefore, people may think that he's inspired The Ring to found Corporism art. However, the truth is that Corprism art has been existed decades ago. Since Ryoshu was a child, Callisto has been seen praticing it as one of its last artists as it had been outdated by that time, suggesting that it had begun even earlier than that. Meanwhile, Jae-Heon only starts crafting corpse puppets around the White Nights and Dark Days. Thus, it should be the opposite.
Yet, according to his cutscene in Roland's realization, he was an engineer when he was a human rather than a Ring members, and given that around that time, The Ring has forgone Corporism for a long time, it is unlikely that he formally learn it from The Ring. Instead, it is more likely that he learn it from somewhere else. And considering The Ring's practice of using art exams to decide who worth their protection, it is possible for The Ring Corporist to spread their art to some residential area in their exams during their reign, including Jae-Heon's home region, leading to the available knowledge about corpse-crafting for Jae-Heon to later acquire and become The Puppeteer.
I know that I have been glazing Index for a while, but when looking seriously, Index has advantages that other Fingers lack.
Index operates not like a crime organization, but like a cult whose members are all zealot who believe in nothing but their god - in this case, the gods of the city who created prescript. And since they most believe in nothing but their gods, it's nearly impossible for them to divide and fight each others on large scale, such cases require individuals to lead and gather them, which is really hard because they trust the prescript over any individuals. And importantly, the prescripts, or accurately, the gods of the city know it all. They have been shown to have absolute vision over what happen in the City. Even if some Indexes want to rebel against them, they will always know and go two steps ahead with issuing prescripts to take care of the business.
On comparison, the Thumb are revealed to be divided into familias that compete against each other. The same for the Ring with their art schools. The Middles run purely on relationship, so inner conflict can still emerge, as seen in Matthias's case. And the Pinky, no need to say much, they have no restrict on members except for when they are summoned for meeting, infighting, either intentionally or unintentionally, are common.
Evidence: Yan's case. The prescript know he's fabricating prescript and issue counter prescripts involving telling other Index members to follow his prescript and make task revolving his fake prescript's command.
As I mention before, the gods of the city have absolute vision over the City. They know everything that is happening, and it doesn't stop at that, they have vision over future too, and not just one future, multiple possible futures as well. This, alongside prescript system, give them significantly strategic advantage. Other Fingers discuss for the plan in the next days, weeks, or months, and in that time, the gods of the city have already seen the best outcome for years, even decades, and issued prescripts to secretly lead to that future without anyone aware, even Index.
Evidence: Yan's case again. The prescript let him free for a while so his fake prescript lead to the destruction of the Thumn branch in Nest L - a significant loss to the Thumb, and his tragedy results in him distort into a living weapon for the prescript and leading to the true ending of the Library, giving back Index its lost members alongside seed of light, shin, mang, and higher rate of E.G.O. Another case is Rien's, the prescript makes him larp Roland even before Roland became a fixer, and make his death looks like that of Bad End Roland's even though that thing never happens in the main world.
Despite her large cyborg body, Gloria is implied to be very young thanks to her speaking pattern and her naivety - she didn't see through Yan's fake prescript like her teammate proxies. Her choice of using loli voice with no problem is also a dead give away
Translate: >!Nosferatu is the progenitor that create bloodfiends or the concept of bloodfiend extracted from the Well become Nosferatu?!<