Just a thought, which you can completely ignore, but what if you told about the information you need in your prequel through a series of dreams. Most of your characters are sleeping at the end of the Veligent, so perhaps you could fill in the blanks that way?
Too much story to cram into a dream… and these characters wouldn’t know this part anyway.
Kade and Serence are both clueless about the deeper machinations driving the story. The bulls, the lions and Lark know that Ayonah has a secret “plan” to avoid the need to blow this world up once and for all, but they have been told to keep quiet about it.