Alright, lemme give this a shot.
1. GC and their friends are Squiddles: there's multiple pieces of evidence towards this, such as the fact that her species is aquatic or has an affinity for water, the use of the term "buccal mass" as well as the implication that there's a large number of members of that species about to play the game (making this the fabled 48 Squiddle session.) Furthermore it would make sense for them to be Rose's species since she has a connection to both The Squiddles as well as the horrorterrors, so I think it's a very likely theory if not nearly confirmed at this point.
So what does this imply?
2. Wait, didn't Squiddles come before Trolls?: Assuming that this is, in fact, the 48 Squiddle session, that would make this the precursor to the Beforus session, implying that the Squiddles are the ones who'll win the game and create a new universe (and, somehow, turn into/create the Horrorterrors afterwards?) but also creating a bridge between BEYOND CANON (Squiddle session) and CANON (Troll session.)
But what would that accomplish? Well, let's think about Dirk's plan for a minute. How does starting a new Sburb session tie into his plan to "make things happen again"? If you consider that the Squiddle session will result in the creation of the Troll universe, the answer becomes clear: It's not just about making things canon again, it's about making Homestuck happen again.
"Homestuck," the webcomic, is the only thing we recognize as being the true canon. Everything else is in a different state of "not canon," because they're not the original webcomic, and therefore, are not "canon". So how do you bring a story that has left canon back into it? You create the conditions for that original story to happen again, so that narrative beyond canon can lead to nowhere else but the place where it all began, the start of the canon timeline of events. Dirk is literally trying to make "Homestuck", the webcomic, again. And the Deltritus session is the bridge he needs to get that show on the road.
I think this could serve as an interesting commentary on how fans interact with stories once they're over, trying to revive them instead of moving on to other stories and other possibilities, creating a parallel to Candy, the timeline where people move on from the story once it's over.
3. The other Deltritus species: So, how does Dirk's species tie into all of this? If the goal of the Squiddle session is to create a loop between canon and post canon, then the other Deltritus species should also tie into something from the original comic, right? And what's a species from the original comic with unexplained origins that also has deep ties to Dirk Strider? Cherubs.
I feel like the idea that Cherubs come from the Earth C is pretty much well understood, so I'm instead going to focus on two things: why they would need to be created and why Dirk would be the one to create them.
First, the way they tie into this whole plan is the existence of Caliborn/Lord English: we know the conflict from the original comic revolves around Lord English's birth and the timeloop that leads to that. In the context of the original comic, the Cherub twins are the only Sburb players whose birth doesn't happen through ectobiology, even though the conditions for their existence and the trajectory of their lives is tied to timeloops. In that sense they're also the only species with an undefined origin. If Ultimate Dirk were to define an origin point for their species, and leave them to roam space until the birth of Calliope/Caliborn, then he'd create another bridge between canon and non canon while also setting up the main conflict of Homestuck.
As for why Dirk would be the one to create them, consider that Dirk, much like Rose and the Squiddles, has a personal connection to Cherubs, through both Calliope and Caliborn, as well as Lil Cal, who we know is actually a puppet of a Cherub in Trickster Mode (see page 5714 - speaking of which notice how the Horrorterrors and Squiddles are also there?), so if anyone were to create the Cherub species, it could certainly be Dirk. I mean, he's fucked up in the head enough to create a species based on his freaky puppet
I think that would also lead to some irony involving Al, since her goal is to stop Dirk from doing all this, i.e. stopping the creation of her own species.
And that's my game theory. Thank you for reading.
