I've always loved the idea of alternia having had an original culture that the introduction of Lord English and doc like fully fucked over and destroyed
Like I've been imagining these things for a bit and I think I have a good rendition of each cast's little religion that they would have had before... Everything
The burgundy trolls are reverent to the past souls that exist, using music and wind and chimes made of bones to ritualistically call upon a Sluagh of troll souls, refered to as The Deadhost.
The brown bloods follow a being called The Burbeler, a being that is made of mud and embodies nature, which has an aspect of all lusii within it.
The Gold bloods worship The Lattices, in which the shape of the atoms are akin to a hive and the engineering of insectoid creatures and just actual engineering are holy .
The lime bloods were a culture less of a specific religion, though they did have a symbol, The Ashgrowth being a burning thicket made of trollhorn shapes, In which the worship was the holy act of burning bridges and then re-forging those relationships stronger.
the olive bloods had a more Celtic kind of vibe, following a being called The Wicked-er Verdiant (a very intentional play on the wicker man, being a giant made of straw, a specific material on alternia called Wicked-er) which is filled with the product of crop harvests and dried meats from hunts.
The Jade bloods follow a supermassive cryptolusii In the moon called The Loommoon, a proposed great moth of creation, that will take the stars and the winds of space and craft a great and beautiful tapestry once the ascension of it comes (This one is the one that gets taken over by doc Scratch and Lord English into what is kind of just a vaguely abrahamic, monotheistic salvation myth and turned it into an ultimately even vague-r evangelical prophecy in which all Jade bloods are forced to care for trolls and mothergrubs despite the implication with all this being that it was simply a communal effort originally).
The teal bloods follow something called The Lawbiter, a vast and all knowing pantheistically vague draconic deity like creature, with if anything some tiamat references at the forefront, in which it exists to ordain rules, depending on the circumstances by which each head is being considered for the rule being asked. It is the god of bureaucracy.
The cerulean bloods follow The Silkwall a massive spider god, Go more accurately the efforts of- another vauge composite arachnid amalgamated from distinct aspects of all kinds of arachnids more than anything. being a shield creature, existing as like a psychic buffer to the rest of troll society, kind of like a Hecate or Hestia figure, vast, deeply unknowable, yet objectively benevolent (as supplemental material had involved and implied that the ceruleans abilities though used in like mind control and subversion of will- were healers, beings that were like a shield and helpers, anything very directly implying that the cerulean bloods were kind of the keeper of well-being that existed in the high bloods in comparison to the low bloods. In effect, the high bloods having coercive magics, the low blood is having powerful magics, and the cerulean bloods exist as an abjurative buffer though still within the range of high bloods) .
indigo blood trolls follow The Starking, a constellation that was destroyed by doc's scratch that originall had the visage of a half Pegasus centaur lusus by which the indigo bloods worshiped its authority, acting in accordance to the will of the people rather than the will of the high bloods (As I really like the implication that the hierarchy as it exists now is the inversion, in which the low bloods were seen as reverent due to their scarcity in life, in comparison to the vast well of kind of hoity knowledge that the high bloods had in being older and more wise.)
The purple bloods follow The Triple Js, a very direct Trinity reference, in which the three beings that embody it are all just the three members of the insane clown posse but mythologized to be these three figures in the Trinity rather than the versions of themselves that exist as the mirthful Messiahs in modern purple blood troll religion.
The violet bloods follow The Vastmist, a very similar concept to The Deadhosts but solely through the power of c and the collective minds of those lost to it both in lusii and in troll.
And finally the fuchsia bloods... I couldn't really think of anything for them and I think that might be the point
Because like the whole idea is that they're so old that they would basically see these religions as just kind of silly, I'd imagine there might even be some even more kind of Eldritch thing, maybe just a lifeblood of the universe kind of mythology, rather than any specific deities
And so effectively when docs grass shows up he does some very specific things, He shatters The Starking out of the sky, He silences The Deadhosts though they're influence can still be heard by a burgundy with a pure heart for adventure and a patience to listen to the wind. The Silkwall is torn down in effectively put up as a tapestry and his (Doc Scratch's) home. The kindest of The Triple Js is slaughtered and it's two brethren are incensed and let astray. All doc has to do is simply emboldened the violet bloods to believe The Vastmist hungers rather than consumes and imbibes passively. The Loommoon It's killed before it can hatch and the communal efforts of raising mother grubs is placed in the deficit of that, in which they are to revere the mother grubs and continue making more trolls to be tortured. The Lawbiter is blinded, though as much as that cue ball headed fuck would want, she just won't fucking die. The Burbeler is washed away by the stark white of the Doc. The Lattices can't really be messed with (literally the structure of atoms, he would have to restructure everything) so the gold bloods are just redirected towards literal engineering.
And The Ashgrowth. Simply burned till there was nothing left.
But what became of The Verdiant? Some say the olive bloods are the only ones to truly stay advised by their god, hunting in both the literal sense but also for community, wishing to reforge those original bonds, feeling the cloying emptiness that is left in the wake of its brethren being destroyed and their pantheon rent asunder. The spirit of forest. The spirit of Beforus.