Now, there was already a spinoff, Smoke Ling, son of a Gunther, covering the son of Gunther King Slayer, the second villain in Phyrra and Cyrus, appearing in the second season, the enemy of Bard. It covered things set about 20 years after the end of the main story of Phyrra and Cyrus (technically 80 years before the epilogue since the epilogue is 100 years from the ending of the main story).
This was a proper sequel, set hundreds of years into the future.
I have the worldbuilding set up.
I have the main character(s). This story would, instead of being an allegory for being trans, would be an allegory for plurality.
Just need to iron out the finer detail points.
Speaking of plurality though, I owe a ramble on that, too.