can confirm everything above. i can't speak to trizza in hiveswap but if i had to guess seeing as hiveswap is a prequel to homestuck, it would stand to reason that gl'bgolyb is also trizza's lusus. as @kit kitthrin said, gl'bgolyb was basically (according to doc scratch) part of why the condesce accumulated power bc she basically had the football to kill everyone at any given point that was then passed down to feferi as she'd gone too far from alternia to reasonably take care of her. that same scratch spiel mentions that heirs were expected to challenge the condesce for her throne, and only two fuschia bloods ever exist at one time. see:

"But the more space she put between herself and Gl'bgolyb, the more she risked weakening her bond with the monster. The bond she and her successor shared with it exclusively could sway, and become strengthened with the younger. Perhaps she grew complacent with the threat successors posed, after such a long history of killing them with ease. Heiresses upon reaching maturity were expected to challenge the Condesce for the throne. It was not merely expected of them by their people, but demanded by their shared lusus." pg 4063