It's funny that I returned to Tumblr to post this Yabanverse worldbuilding stuff and got around to the Gosamyrs, considering that the entire idea of the Gosamyrs was rooted in Tumblr culture of the 2010s
If you've been here since the mid-2010s, you probably remember all the æｓｔｈｅｔｉｃ (美的) posting that was popular then as Zillennials discovered the magical world of 80s retrowave/New Wave punk/Outrun/90s vaporwave/Memphis aesthetics. Remember that time the 2010s wanted so desperately to be the 1980s? Things like the retro anime aesthetic, side-shaved haircuts, synthwave music, VHS aesthetics, Japanese city pop, and Mom Jeans were deliberate attempts to bring back certain parts of the 80s. To some extent, that "Zoomers Discover the 80s Existed" nostalgia wave never really ended; it just became oversaturated, and now everyone's all about the Y2K and Frutiger Aero aesthetics.
But the Yabanverse formally got its start in December 2017, and in trying to make my "Legally Not Saiyans" in the form of Yabans, I figured very early on that I wanted to heavily invoke 80s aesthetics, partially because the Saiyans already were doing that (again, take 80s aerobics and fitness freaks, cross that with Battlestar Galactica-tier sci-fi samurai armor, get some glam hair straight out of the LA Strip and the Batcave, and put a monkey tail on it with a society fit for an anime OVA, and you have the OG Saiyans). However, Yabans and Planet Kollidor in general were aiming more to ape (badumtish) the look of 80s heavy metal, with its airbrushed desert chrome, steel and leather, blood and thunder post-apocalyptic hell-riding road warriors, big muscles and big egos of early/mid 80s British heavy metal, power metal, and thrash metal, the kind of stuff you'd see in Heavy Metal magazine or some Rambo/Commando/Predator/Conan-esque video game cover-art made by a Frank Frazetta-clone. You know, the part of the 80s the 2010s was conveniently not interested in reviving.
But the Saiyans were contrasted by the Freeza Force and their ilk, and I did quite enjoy the likes of Zarbon and Jeice especially, with their fruity-colored skin and aggressively flamboyantly 80s style of fashion, and decided to run with them specifically to create the Gosamyrs.
The Gosamyrs, to be fair, were already a thing from another story of mine, essentially a "Vaporwave Skyrim" story on a planet that was essentially the standard pseudomedieval European fantasy world that somehow reached the equivalent of the 1980s (and the 1780s for the Gosamyrian elite). So instead of Elves being treehugging archers and Orcs being green-skinned chimps in the wastelands, these elves were synth-pop glammy hypercapitalists and the Orcs were denim and leather road warriors.
For fun, I crossed these with the Not!Dragon Ball that was the Yabanverse at the time, and when the Yabanverse returned to being a DBZ AU in 2023, they came along, though admittedly the Gosamyrs are a bit redundant if Zarbon's race and the Brench-seijin actually do exist in the Yabanverse (even if they're a Universe 23 variant)
I've yet to do something more with the Rongo and Kusurian, but the latter actually is as old as the Yabanverse itself, back during the proto-Yabanverse.
Kusurians essentially being excessively strong martial humans, who may even be the precursors of the Saiyans themselves (as well as several other races in the universe) insofar as they possess a "primordial form of Super Saiyan"
It was always a deliberate play on a Toriyama-style villainous race, and it actually fit in with Super somewhat by accident when there was a mention that Universe 6 Earth was destroyed by warfare and terror. The Kusurians essentially super-ancient Earthlings exiled after some forgotten war in the distant past to outer space, and their empire seeks to return to Earth to re-establish Earthling domination. So the fanfic concept was that Son Goku and friends have to face off against space-Earthlings who gather the people of Earth to their side, essentially putting the conflict squarely in the realm of "you have to defeat the same people you dedicated your lives to protecting"
And when the Super reference to U6 Earth was made (this was around the time of the U6 Tournament arc, right before Goku Black), that then evolved into "U6 Earthlings were foolishly resurrected by the Super Dragon Balls because of Champa's gluttony without factoring in the context of why they exterminated themselves, and it turns out U6 Earth is essentially the same as U7 Vegeta (the planet, not the Saiyan), complete with a scene of Planet Sadala being invaded by a pair of ridiculously strong Earthlings, and Cabba has to go to Vegeta (the Saiyan, not the planet) for help"
Adapting it to the Yabanverse shifted it even moreso, since it's not set in the same universal stream as the DB-verse, so technically the Kusurians could exist there, but the ones in the Yabanverse are different and based far more heavily on "50s googie" or "space age/raygun" aesthetics to play off the Yabans (80s heavy metal/fantasy), the Gosamyrs (80s glam/retrowave), and the Narakans (90s/early 2000s edgelord/nü metal).
Earth in Universe 23 is probably not their actual homeworld goal either.
